Comment by TFNA

I was active in Wikipedia from 2002, and there was a lot of idealism back then among editors that it would be a "reference for all knowledge". Those wishing for a more constrained site eventually won the day, and they had good arguments like yours. But even today, you can find certain pop-culture lore, for example, covered in insane depth on Wikipedia; not everything was sent away to Fandom wikis as Wikipedia's policies evolved. So, it doesn't surprise me that people continue to ask, like here, why WP can't be more ambitious.