The Outer Wilds
All due respect to the other recommendations in this thread (The Witcher 3 is in my top 3 favorite games ever), but I get the sense you're looking for a similar vibe - that self-paced, quiet, almost lonely exploration where, though you do have a goal, the point of the game is to wander the world and discover things. While most of these recs (and most open world games in general, so it's understandable) have a strong story focus, The Outer Wilds will give you that quiet, unguided exploration BoTW does so well.
(And I know explicitly turned down souls-likes, but Elden Ring also hits that vibe super well. If you're really stuck for something to play, it might be worth a try with one of the magic-focused builds that significantly reduce the skill needed)
I wonder if at some point he ever read about how 1 in 7 (or whatever) humans are descended from Ghengis Khan.
I know he says all kinds of wacko stuff about fertility rates and population collapse, but when have his motivations ever been even that bit more complex than wanting to imitate/join the cool/funny thing he found online? I seriously wonder...