He says in the thread he's near the end of an completionist run. It's not like it's a stunningly short game. Go look at the time it takes to complete compared some of the similar games it's I've seen it compared to over the years:
https://howlongtobeat.com/ (comparing non-completionist main+side quests)
The Witcher 3 - 102 Hours
Dragon Age Inquisition - 87.5 Hours
Fallout 4 - 79.5 Hours
RDR2 - 78 Hours
Mass Effect: Andromeda - 63.5 Hours
Cyberpunk 2077 - 50.5 Hours
GTA V - 47. 5 Hours
Dark Souls III - 47.5 Hours
Horizon: Zero Dawn - 44 Hours
Nier Automata - 37.5 Hours
Witcher 2 - 34 Hours
Deus Ex: Human Revolution - 31 Hours