The first one, when they dropped third parties and removed the already-bugged step count under close-by pokémons. It's purely anecdotic, but after that release

The first one, when they dropped third parties and removed the already-bugged step count under close-by pokémons. It's purely anecdotic, but after that release, popular spots (with multiple pokestops and arena in one place) usually crowded with more than 50 people playing actively were down to one dude on a bench. Sure the "loud minority" is not representative of the whole game's community, but they were it's core players. They shaped the game's community (and niantic didn't helped) from the beginning. And it didn't help when those people decided to stop playing. Back to server's issues, Google CREs did a very good job during these times. They can't be blamed for trying to scale an app that was absolutely not designed to get this high.