It's a complicated scale based on difficulty, the story, the length, etc.
If a game that I feel so far is around a 7/10 or lower and it's a long game, I'm checking out. There are too many games to play out there to spend dozens of hours on a decent at best game.
If I really like the story (Jedi: Fallen Order) but do not like a good deal of the gameplay, I'll stick it out if it's not too long or difficult.
If it's a meh game with some easy trophies/achievements that can be done in 2 hours or under, I'll usually stick it out.
Persona 5 Royal is one of my favorite games ever. But if it's not hooking someone after the first dungeon or two, abandon it. It's a 100+hour game on most difficulties and you have better things to do with your time than spend that long on a game you think is decent at best.
Lifetime Sales Predictions
Switch: 161 million (was 73 million, then 96 million, then 113 million, then 125 million, then 144 million, then 151 million, then 156 million)
PS5: 115 million (was 105 million) Xbox Series S/X: 40 million (was 60 million, then 67 million, then 57 million. then 48 million)
PS4: 120 mil (was 100 then 130 million, then 122 million) Xbox One: 51 mil (was 50 then 55 mil)
3DS: 75.5 mil (was 73, then 77 million)
"Let go your earthly tether, enter the void, empty and become wind." - Guru Laghima