I have heard such ideas before, and I think one big reason is because the some of the most degenerate members of society are fans of anime and video games, however that is putting the cart before the horse.

Trans love make-believe and escapism because they hate reality, so they flock to these things. When we look at Japan, however, they aren't overrun by troons, although they do have a large amount of people who are discontent with real life and love the escapism anime allows. Still, fantasy being popular with certain types of people is a symptom, not a cause, it doesn't mean all who enjoy it are degenerate, and many anime can be fine in moderation (although some is strictly negative).