I didn't feel the "survival" mechanics were detrimental, but rather a missed opportunity. I can understand why Rockstar, in the end, pussied out and scaled them back. If you go on any site where people criticize the game, one of the first complaints you'll see is the survival mechanics. Just the mere existence of them, even if it doesn't really matter gameplay wise, is enough to scare plenty of people away, because it's perceived as annoying busy work that gets in the way.
To me it also ended up being my main complaint about the game, but in the exact opposite way - I hated that I could ignore the system. I wanted a hardcore mode where you needed to eat every X hours and taking 3 shots would immediately kill Arthur. Surprisingly the PC version is still lacking such a mod sadly.
I also wish that the "survival" elements actually mattered, in an optional hardcore mode or otherwise. Not surprised to read about casual players complaining about having to engage those mechanics/elements even though they're inconsequential/entirely optional in practice as I find that the opening chapters of the game did a good job selling the illusion that those mechanics mattered/were needed, despite it being a one-size-fits-all difficulty AAA game.
The goal might have been for the more casual player/kids who don't enjoy that kind of stuff to quickly get annoyed and try skipping them so they'd quickly realize they don't need to engage with them and move on and play the game more gta-like, and also for the players who do enjoy those kinds of mechanics to simply keep engaging them naturally not realizing that they don't really matter. Even if the mechanics don't really have a significant effect on your likelihood of surviving, the game does offer other ways to validate your decision to keep engaging them: the way camp npcs complain and act when low on supplies, the way your gun's appearance changes when rusted, the way npcs react to you when you're an unwashed unkempt bum, the way your character moves when he's improperly dressed or needs rest etc. It's not as good as there being a real need for you to engage those mechanics -not as good as dictating your chances of survival- but it's not as bad as larping in a vacuum/TES game.
I'm at the St Denis chapter now and feel like the protag's near invulnerability and the excess of money are the bigger issues. Considering skipping deadeye mode/gamepad autoaim and not looting random npcs/containers if this keeps up, or on a new playthrough. Never had to use tonics.
The exploration/traversal is also too dependent on the minimap (worse than 3d markers you can use in games like the AC series) and long horse trips can quickly get tiresome (worse than autowalking/smart horse controls of BOTW/SOTC/modded TW3).
As for mods:
https://www.nexusmods.com/reddeadredemption2/mods/125 Haven't tried it.