If you want what’s changed it’s probably that people discuss them more

This is true, but it’s more important than it sounds – the “discussion” (which also includes fanfic, fanart, etc.) is part of a feedback cycle. 

If you’re St. Teresa, you can have lots of fun sexually obsessing over Christ.  But this actually requires a lot of imagination and a lot of focus, because the Christ fandom is not giving you a whole lot to work with in terms of inspiring material on that front.  And if you’re not in a rich household or a top-class monastery, with access to art and literature, it’s giving you pretty much nothing.   For your average horny teen, it’s probably a lot more rewarding just to go play grabass with the boy/girl next door. 

Whereas, now, there is a Library of Alexandria’s worth of immediately-accessible material to guide you through your journey towards a sexual fixation on cartoon  ponies.