Ohboy. Are we really gonna start that here? I'm biting anyway.
Fiction can affect reality, but not the way most twitter antis say. I only like adults IRL and strongly prefer ojisans and yakuza BL. I don't think occasionally reading a BL about high school boys fucking each other is going to turn me into a pedo. It's not hot because of the characters' ages or immaturity but because being a teenager is full of emotions and first times. I was a horny teen, we've all been horny teens, they're way more relatable than a BL about rockstars.
On adult and minor pairings, why do antis always assume that people only relate to the adult? A lot of folks find adult/minor BL hot as wish-fulfillment from when they were teens crushing on out-of-reach adults.
Same for rape, why do we assume people relate to the rapists? Most rape fantasy is about BEING raped or losing control in some way. In rape BL the uke is usually the PoV or main character.
If someone notices their tastes getting very extreme or dangerous, they should get help. If someone knows that rape or adult and minor content is a source of trauma for them, they should avoid BL. We don't just need content or trigger warnings, we need better tagging and filtering systems in general.
Antis worry about kids getting oversexualised by BL/fandom but these are nothing vs. mainstream porn. I still don't think it's good for kids though. There's some shit that really crosses a line for me personally, eg. Killing Stalking, I think that one and its young fandom have done damage to people.
BL can often rely on homophobic tropes, but it has helped make Japan slightly less homophobic overall and helped a lot of people become comfortable with sexual feelings.
TL;DR - I don't fully disagree with antis and I don't enjoy rape or adult/minor content myself, but their no-nuance, scorched-earth approach isn't sensible or helpful.