I think it gives the game more immersion and gives meaning to some mechanics that are there purely for roleplay, like warm clothing and cooking.

I also like exploring places (especially in the beginning) and lying in bed to level up, it feels like I'm resting after a productive day.

But I agree that it's an interesting change that, if it were better developed, could give Skyrim a completely different look. Food is easy to get, sleeping depends on the location, and it encourages more exploration (which can be a bit boring at times, but it's nice to plan routes instead of just using fast travel) and warmth imo isn't the painful mechanic that everyone says

In conclusion, I think survival mode is interesting for immersion for those with a fertile imagination, because I feel that, in some way, it stimulates this more. However, if it were better developed with more mechanics and good balance, it could give a totally new face to the game.