IDK, I think 10 hours is plenty for any game, and 2 hours is enough for most. By two hours, you’ve likely discovered the core gameplay loop and seen how it handles progression, and by 10 hours you’ve seen whether that core gameplay loop changes throughout the game.
I don’t like negative reviews for games when they’ve spent double the time HLTB gives for a playthrough. I don’t expect to play much more than “main + extras” on any game, so any review that’s expecting content beyond that just isn’t useful for me.