Mainstream? "The boys" is one of the most popular series on Amazon prime. It is certainly not a basement cult series known only to a few nerds. Yes it is based on an old comic. But so what. Most "stories" are recycled or "based on". Shakespeare did this as well.

On Amazon, yes. Not in the cinema. Cinema is what the original article is talking about.

Perhaps the difference is important. Maybe not. Certainly the boundaries between "cinema" and "tv" are blurred with many people consuming most material via streaming. But maybe "series" can take more risk with the material than a "movie" just because the unit cost of a single "failure" can be amortized through the season if the the majority of episodes shine.

I believe it's the market/censorship dynamics driving this; films targeting China and India (which is most really big budget Hollywood films) have much tighter control because the target markets accept less.

Whereas streaming is smaller, cheaper, and targeted at more local audiences.

If we can't count The Boys because it's based on an older comic, what do we say about the MCU movies central to the thesis?

agreed, and The Boys has had success exactly because it stands out against the current normal action film/tv