I'll state an old classic that is seen as a genre defining game because it is: Myst. Yes, it redefined the genre... in ways I fucking hated and that the adventure game genre took decades to fully recover from. It was a pompous mess in its presentation and was the worst kind of "doing action does vague thing or nothing at all, where is your hint book" puzzle gameplay wrapped in graphical hype which ages pretty poorly as far as appeal qualities go.
So many adventure games tried to be Myst afterward that the sheer budgetary costs and redundancy of the also-rans crashed the adventure game genre for years.
The story just did not grab me at all, I found the art style incredibly ugly, and despite liking a lot of games with relatively similar playstyles I did not enjoy that at all.
I feel like people were just really excited to see a cyberpunk game, which at the time was definitely an underserved market.
Mankind Divided had all the problems of Human Revolution and made them worse.
It even did the turbo whitewashing thing of clumsily making cybernetic upgrades into a racism metaphor and then not applying it to the augmented main character because that might be unfun and inconvenient.