I really liked how Valheim's smoke mechanics required me to incorporate some kind of chimney or smoke solution into my builds. If there's no mechanical reason for me to build something like a chimney, I end up either not building it or feeling a little disappointed that there was no purpose if I do.
I feel like cellars are a similar existing nudge. If food preservation and cellars hadn't been a mechanic, I probably would have ended up with all my food stored in a pile of chests in my main room, as usually happen in my minecraft bases.
I have a semi-related desire to see fire safety apply to more things than pit kilns; I kind of wish that the standard campfire required a little preparation (maybe an opportunity for the tutorial to teach new players about packed dirt and rammed earth), leading to a mechanical need for fireplaces (though preferably paired with it being easier to recover from screwing up a fire--maybe limited spread, or converting blocks to "scorched" variants instead of destroying things).
