It's hard to quantify a success metric for a live service game. Players usually determine it based on their opinion of the current state of the game, and the developers base it on more empirical figures such as active subscription count and revenue stream. Obviously this is a pretty big simplification of how the parties involved think, but it does outline the natural disparity that occurs organically in a developer-player relationship. So what we then tend to look at is how the developer bridges that gap (as we should rightfully expect them to do).
Yoshi P and the lead members of the development team did a wonderful job of this over the course of about a decade. It was a delight. I have noticed a strange behavior from the dev team since about this time last year that's been concerning however, and it's that they don't seem as engaged with us as they used to. It's like they've pulled back from the player base for some reason. Everyone isn't going to stick their proverbial finger in the air to determine the wind direction here, but subconsciously I feel like folks became attuned to this mild division at some point and this in turn has magnified their reactions to YoshiP's completely tone-deaf and out of touch response as a result. It has scared people who don't want to lose one of the last vestiges of a game dev having a good relationship with its playerbase. A lot of us were there for WoW and Destiny 2's transformation into "the villain," (it's complicated and I don't feel like picking different words) and they're scared that it's going to happen here now. That's why everyone is blowing up rn.
I do think that YoshiP stepping down would be the worst possible thing for this game tho. The folks who think that's a good thing have no idea how much of a death knell that would truly be, or how fortunate we are to have YoshiP at the helm of this game.