I like them if I am doing a full playthrough, though not if I have specific content I just want to do, especially other mods.

I know people throw around "immersion" a lot but for the most part yeah it does help with that , it adds ongoing costs to adventures (honestly skyrim needs money sinks) and it tends to help slow me down and break me of the habit of just rushing objectives. Frostfall is the one that is a little up in the air, I pretty much always lower the exposure rate slightly and while I like having to prepare to go to cold areas and frostfall has given me some amazing moments it has some issues. A lot of places that are really cold don't have npcs that act like they are and particularly around the college of winterhold you can end up freezing in the time it takes for NPCs finish a scene. I remember having to run off to warm up twice during the tour because I would freeze to death which is admittedly kind of hilarious but also annoying. Though in my recent playthrough the mystic focal points emit heat (not sure what updated or was fixed in my load order to do that) which made it not so bad.

I don't like most survival games, the exception would be Subnatica and maybe story mode of The Long Dark if that ever gets finished. The reason is that most survival games are, unsurprising, all about survival with not real end point and are generally pretty lite on story or NPCs (because being isolated is kind of needed to make survival hard). When I mod skyrim to have survival mechanics it doesn't turn the game into a survival a game, it's typically not very hard nor do I particularly want it to be hard since it's not the main thing. It is still primarily an rpg.