Yes, the sim point economy is a complete joke. Like all modern games of this type, it requires that you self-impose restrictions and design your own experience. I pretended that the sim point costs were far higher and only purchased a few essentials in each run, easily ending the DLC with on the order of 150,000 points. It's a major problem. Not the only one (somehow they still didn't notice that your suit barely ever takes a scratch and yet you find Suit Repair Kits around every corner), but arguably the biggest.
However, if you can control your spending, the game structure actually becomes pretty interesting. Resource gathering with the timer may be pointless when you're prestocked with ammo, grenades, and hypos, but in the absence of such things you have to start scrounging and making immediate decisions about what to loot, recycle, and craft. There's a tension between your goals here -- you want to complete objectives and escape before the timer wears out, but there are obstacles in your way which require resources, and so you have to explore, fight, and gather first. The player is encouraged by the timer to play in a way that the base game actively fought against, as abusing Operators (or worse, drinking fountains) and hoarding crafting material and specialized grenades that you'll never use "just in case" is a big waste of time, and you stand to lose more from death than you gain by holding onto loot. Early on, Mooncrash held some of the best moments I've had with Prey, where my path was blocked by dangerous groups of enemies that my character didn't have a natural solution for, prompting me to adapt and introducing some genuine tension and risk. I probably threw a maximum of 5 Typhon lures over the course of two playthroughs of the base game, while the presence of lethal Weavers, Voltaic Mimics, and Thermal Phantoms made me use 2-3 just on my first real run in Mooncrash (not counting the tutorial). Some other design choices that were smart in my opinion were the introduction of Typhon gates that require you to eliminate all nearby enemies before you can pass, and the time delay loop items dropping from powerful enemies, encouraging you to engage in combat as much as possible because time is in short supply (these help greatly against the "just sprint past everything" problem of the base game that would be even worse in the DLC otherwise). Many of the enemy designs are also greatly improved, I adore the Psychostatic Cutter (seriously, that and another tech weapon would have solved the base game's weapon variety problem), the low-G moon environment is a lot more fun than any zero-G section in the base game, and the new jetpack boost is so stupidly fun to use, balance be damned.
Just like the base game, though, most tension and challenge in gameplay starts to wear down to nothing as the DLC goes on. I don't think it's all an abject failure -- there's a decent attempt to scale the difficulty with harder enemies, more hazards, and faster corruption timer as you complete objectives and have to start optimizing to get more people out in each reset of the simulation. But it's not enough, and the permanent character progression eventually messes everything up even without the sim points. I originally thought that Neuromod progression would be reset every time you restarted the simulation, but it's carried over, even when you get killed in a run. This indeed means you could just grind all of your characters out and then cheese through a perfect 5-character escape run (hell, this is close enough to what happened to me without any grinding). Much of the tactical decisionmaking of the early parts of Mooncrash vanishes, and you can eventually sprint to your escapes with stacks of resources transferring from one character to the next as you truncate enemy respawning with crafted time loop delays and zap the Typhon gates with electrical/EMP damage to zip past all encounters. I wasn't feeling Crew Quarters/Deep Storage levels of boredom by the end, but I was pretty disappointed especially from how glowingly positive I was on Mooncrash at first.
Consider the alternative design, where everything costs a hell of a lot more sim points and all progression other than fabrication/chipset plans is reset between simulations. You also wouldn't retain any scanned Typhon powers, the piloting connectomes for the shuttle escape, nor the Phantom Genesis experiment data for the consciousness upload escape (I was frankly shocked when I discovered the latter were one-time requirements). Maybe the difficulty would scale a bit more aggressively too as you complete more objectives, but I'm not sure that would be necessary in this paradigm. Every run would require some thought about which character to use, in which order, and with which escapes. This in turn requires decisions to be made about how to spend Neuromods between and within each character's skill tree. Someone's got to learn piloting to escape in the shuttle, but you're also going to have to learn repair with Joan AND hack with Claire to use the Mimic portal. You need someone with a psychoscope to access some of the more powerful Typhon abilities (knowledge of these would still be shared among all characters in each simulation), so Riley's probably a good choice early on, and she has her own dedicated escape path so you're still flexible with the others. And that flexibility would be important, because of the randomized elements in each simulation. You won't know in advance which escape pod is going to be operational and which is going to be broken with the spare navigation module, nor the location of Angela Wagner's and volunteer V-014551-P04's bodies for the piloting connectomes and the phantom experiment respectively, nor which hazards and enemies will be present, nor which parts of the moonbase will be unpowered. In each run you have to decide how much of your time should be spent scouting out and gathering to help the next run, and how much should be spent working on critical objectives. There are some natural features that emerge in this paradigm -- Typhon gates remain impactful and psi-oriented characters have a choice to make about how many alien powers to obtain depending on their ability to produce electrical interference. Time delay loops remain a finite and valuable commodity that keep the player under a time pressure while encouraging optimally combative/explorative play, especially if the fabrication plan proper is removed and the only way to fabricate it is to invest in Joan's Reverse Engineer skill (also, it should cost 3 synthetic, mineral, and exotic, not 2). You might even give a single shit about the Kasma bounties (muh WolfenDOOM kewl bonus challenges) to rack up more sim points as you're gearing up for your runs. Most importantly, all of this would keep the tension, challenge, and adaptive thinking at which Mooncrash initially excels intact as you learn the ins and outs of the moonbase, by multiplying the complexity of the tasks the player must accomplish alongside the standard difficulty increases.
These elements are the potential I initially saw in Mooncrash, which at first blush appeared to me as a genius culmination of innovative and coherent systems that really broke new ground for Immersive Sims -- we haven't seen this kind of successful genre hybridization since the classics. But as usual with Arkane, this had to come with massive caveats, and I remain ultimately confused what their design priorities are. For a long time I figured they were just continually splitting the difference between their hardcore and casual audiences and struggling to find a balance between the two. But the Survival Mode options were a real headscratcher when viewed in this light, because they're clearly geared for a more hardcore audience and yet their balancing is so impotent that I wonder who the hell they're even targeting. It's similar, but not quite as glaring, with Mooncrash, which has some major balancing issues of its own but can be enjoyed with a simpler algorithm of self-restriction (don't spend sim points) than the base game, which requires a lot more moment-to-moment self-control about how often to save, how many Neuromods to craft, which skills to avoid, and how often to use Operators to keep things challenging and fun. I'd love to fix all of this with mods but... it might not be possible.