Retiring would not be ‘endgame’ material, in that sense, and I prefer cata this way.
I feel similar to what has been voiced previously here: the reward ought to be lore, not ‘completing’ the game. Much like I can follow a job for part of my life and then move on. It’s part of the story but it’s not the goal.
If retirement led to your character and their base being implemented as npcs/part of the map, how would you handle successive play-throughs with them present? Would they be hostile to your pc? I ask this because locating a well-equipped survivor home by memory would make said new character’s life go from ‘hell’ to ‘assured safety’ really quickly.
Seeing permanent changes to the world like that would add a long-term sense of control over the survivor’s world (really cool), but at the same time, would change game balance ridiculously.
I already have a habit of doing this when my character dies: I make a new one, and run to my corpse to pick up their thus-far accumulated loot for a head-start if I can.
Mitigating this would be alternative location starts: we have this already with randomized shelter placement, as well as non-shelter start locations. Also mitigating this, I feel, would be the NPC overhaul, which will alter significantly how we interact with anybody, previous character or not.
Just a collection of thoughts. I really do like that retirement option.