Good point, but some consequences of the player's actions are still immidiate in nature, i.e. combat outcome. I doesn't only mean the death of your own character, which is obviously game over, but the death of any of your party members if it's a party based game, number of consumables used etc. With a limited save system, you are much more pressed to put up with the outcome and it also provides for a more tense gameplay which is a part of the gaming experience. It's not a difficulty or playtime stretching thing only. Also, I don't think that "cumulative consequences" should be the only C&C mechanics. It just doesn't make sense, you may want situations in which your decision has an immidiate effect.
Being "pressed up to put up with the outcome" and providing "more tense gameplay" is just another way of saying that it makes the game more difficult - and this is for the wrong reasons because instead of the game relying on you mastering its rules, it relies on you wanting to avoid repeating sections of the game you've already proven you can beat by introducing artificial limitations to the game's interface with the player (with "interface" here i do not mean just the buttons, menus, HUD, etc but
everything the "ruleset + world state" uses to communicate with the player). Also it doesn't have to be about game over - death of a party member, a "bad" choice in a conversation screen, etc are the same thing as a game over: undesirable states.
And again i'll use controls as an example: imagine if you had to use only arrow keys to move and Delete/End/PageDn to look up/center/down in Doom 2016. As far as the game's rules are concerned you can aim anywhere you want, so everything in the game's ruleset still applies. And i'm sure everyone would agree that the game would also be much more challenging and difficult by doing that. However i hope we'd also agree that this challenge wouldn't come from the game's own rules being challenging - not from a better AI on the enemies, not from more devious level design or resource management or weapons stat upgrades or anything along these lines - but instead it would come from the way the game interfaces with the player.
I disagree completely with this notion that save systems lie outside the ruleset of the game. Arcade games and roguelikes are two very obvious counterexamples. Their save systems are integral to their respective genres and the experience changes completely if you introduce quickloading. No longer would they be tense genres requiring true mastery of their systems to succeed. No more careful resource management, no more long-term consequences of any kind
Arcade games were designed so you can waste coins so they were intentionally difficult and in addition they were made for play in public environments (arcades) so saving wouldn't really be possible considering the hardware at the time (AFAIK in recent years it is possible to save your game's state in some arcade machines in Japan on customer cards, but this is a niche anyway).
Roguelikes restricting saving is IMO an arbitrary decision that isn't necessary exactly because the world is randomly generated you do not gain much from being able to load. Many roguelikes do allow saving and loading - either by default or by an explicit game mode - and people play them just fine.
But yes, these limitations do make the games harder, this is never something i argued against - what i argue is what i replied to Pentium above: that difficulty is cheap, it comes from the game's implementation instead of the game's actual rules. After all by the time you save you have already made several choices which they have or can have consequences and those would still apply.
after all, if you mess up you can just rewind a little bit and do something different!
And there is nothing wrong with that, the game's rules should not be so easily defeated by an implementation detail like the savesystem, especially in genres like RPGs where your character's statistics (which are part of the game's rules and state) are supposed to be more important than the player's abilities (e.g. a character can either pass a skill check or they cannot, being able to saving shouldn't affect this - even if there is a randomness element by making the random number generator's state part of the game state). But this applies to other genres too: in an adventure game you can either solve the puzzle or not.
Even in games that rely on player skill, like a platformer, you can either perform the control combinations in the expected time sequences to pass the obstructions (e.g. jump over a large gap by run+jump at the right position) or you cannot. After you have demonstrated (to the game) your ability to do that there isn't a reason to put the player in a position where they have to repeat something they've already demonstrated their ability to overcome just so that there game's length and difficulty can be artificially increased. This is why i call relying on implementation details like the savesystem a sign of bad design: even in the case of player skill based games, the game should introduce something different and more challenging for the player to overcome instead of using the repetition introduced by a limited (intentionally broken) save system.
In general, IMO, if a game's difficulty can be defeated by the game running under an emulator with savestates (assuming one exists) then the game wasn't that challenging in the first place and relied on gimmicks for artificially increasing its perceived difficulty.
Of course i will repeat here that this is just a small design issue i'm describing here, i'd play a game - and have played a ton of games - with design issues way more glaring than just their reliance on the savesystem for difficulty if i found the game in question interesting regardless. But if there is a question between "savegame limitations" vs "no savegame limitations" then i'm certainly on the latter camp and i can explain why i think that.