It’s far more mainstream now, quit it.
I said thru television broadcasts.
There’s a reason why anime for the most part does not air on live tv outside of graveyard slots and the toy-selling Anime (Pokémon, Beyblade, etc).
And this was happening before the death of television but that in itself definitely didn’t help
the internet was alive and well in the 90s brah
anime is much more accessible now than it was even in the early 2010s tho
Around late 2000s there was definitely an anime and later American action animations exodus from most of TV
Outside of a select few most of those products have transitioned to various streaming services and most of American cartoons airing on TV right now are comedy/non-episodic shows
I also wouldn't American animated shows are "mid" (well except for the adult comedy ones, I think most of those are kinda mid), but the children shows are just marketed towards children and thats how it is
I don't think that's a reason it's mainstream at all, but it does give some incentive to look elsewhere for other animation media that have been existing for decades and were already popular outside of America.
If anything, very episodic television shows in the US is what keeps people hooked and rakes in the views. Said shows being "mid" is just subjective.
Marketing strategies play a huge role in this too, especially with fan-services and advertisements with product. A pushed media, regardless if it has more positive qualities than negative, will bring in a newer audience when eyes are caught; this is especially the case with partnered endorsements (huge figures/people, brands, food chains, entertainment businesses, etc.).
A runoff ultimately leads to the tiring divide of casuals and elitists.