>>282397922
I do think that some of what you're writing has some merit regarding majority of BL(so not fujobait) fujos moving onto other mediums like novels, manga, live-action, etc. which have a wider variety of series to enjoy. Though I think that if YOI was released today, it would still be pretty innovative enough with the sports BL premise to attract a similarly large audience.
However, with how much larger the anime-sphere has become post-covid, specifically for shounenslop, I'd doubt that the YOI audience size would be proportional to the anime community. For better or for worse, it'll likely just be represented as a smaller subset of the anime-sphere in present time.