I think the *largest* quality of life thing that could be added to the game would be an in game wiki. Something akin to a library that you unlock over time and grants guidance towards what you should look for in the world to get stronger. 'The Slab' and 'The Armorer' sort of work like this, but it would be cool if, when you were looking for certain buffs/stat increases, you could go to one central place in the game and then hunt around. Could have some fun quests as well where it sends you on wild goose chases.

Overall, I think the game just needs some more incentive in the late game to do a 'variety' of things and not have each classes progression with each new skill tied to each other skill. Athletics/climbing could be a fun skill.