What makes physical death so special that you do want to exist before it happens, but don't want to after? Why not pick some other arbitrary event, like say, the next New Years?

Some people enjoy playing games in 'Hardcore' mode (see e.g. Subnautica) where if you die, instead of respawning, the game ends and your save file is deleted.

Spending the rest of eternity with other human beings is not very appealin.

for me it's the fact that I could theoretically end it (modulo quantum immortality, my worst nightmare). the afterlife is usually sold with "guaranteed forever". I've been in so many situations that you might think "oh I wish this could go on forever" and then regretted it, that I want to make sure there's a way to pull the plug.