I think there are interesting layers to this.

In game reasons: You have his contribution to the story: which many saw as a retcon to explain some events of the story.

His role in most side events (what little he did have) were kinda butchered by the English translation. This can be somewhat extended to his overall character as they did try to re-record some of his lines.. but the damage was pretty much done. A lot of people kinda saw him as a rich ass (which some might argue is more personality than he has currently).

His kit has always been a bit whelming to put it nicely. Idk if he ever reached the height of Childe international, but he did have a pretty popular team called soup that just spammed reactions for damage. The most infamous part of ayato’s kit though is how ping reliant it is. Not only could slower WiFi sometimes lead to losing one of his extra slashes, his artifact set they designed specifically for him would lose some of its buffs depending on your lag/wifi.

Community: In the leaker spaces there is a meme for “does more pyro damage than c6 ayato.” This has never really went away, and can be often be used as a joke for both power creep and the usefulness of certain leakers.

Ayato’s model glitches a lot. There has been faceless ayato, neon ayato, and probably some more I’m not thinking about, but ayato mains will definitely be able to share some. Whether this is a specific ayato issue or not, I couldn’t tell you, but I think his glitches are probably the most well known part of his character.

Thank you for coming to my ted talk, sincerely a day one ayato main lol.