Then you must be old. Even in western countries Spy x Family (which the character is from) has sold millions of copies, while most people read mangas online and won't be counted. In the country I am from I frequently see people wearing merch of it, mostly because Uniqlo has had a successful line of it. And that is just one manga/anime out of hundreds of popular ones.

Using anime characters is similar to boomer nerds referencing Marvel/DC comics , Star Wars etc.