Fallout 76 didn't ruin New Vegas
Ultima online wasn't a "cancer" to the gaming industry
I wish Final Fantasy XIV ruined the franchise so we didn't get the abomination that is the latest two installments.
Greedy shit developers make shit products, no surprise. But GemStone, Asheron's Call, World of Warcraft (the early years, I can't speak to the latest) and other forms of long-term games offer a chance to experience a world for years in an additive environment instead of waiting for the next installment of starting at ground zero again.
If you want to play the same game over and over, there are plenty of those.
Live games are for ever-changing environments.