This is maybe only tangentially related, but my most hated recent trend in genre fiction is "Your Fantasy story is actually Sci-Fi".
Numenara/The Ninth World is probably the most popular example (and I almost give it a pass for ingenuity), but it seems to be the go-to for trashy low-budget fantasy and webcomics; and it's also really popular in fan theories (Game of Thrones and AtlA being big examples). And there's always media that sort of straddles the line between the two (the new She-Ra: Princesses of Power show being an example; fantasy themes, sci-fi setting).
Of course, you could say the same thing about Star Wars. But I guess the difference, to me, is that Star Wars is unabashedly Sci-Fi. She-Ra tries to hide its Science Fiction behind of veneer of Princesses and pseudo-magical superpowers.
Another trope I am not very fond of is nanotechnology where there are trillions of tiny robots that can effectively act as magic. It just feels like a lazy way to write science fiction because you really want a fantasy.
Agreed completely.