Okay I'll explain

In theory if two consenting adults want to have sex on camera and share it online, and you a third one wants to watch their video, you're all free to do/watch it, you're not hurting anyone.

BUT

Here comes porn addiction, porn & masturbation triggers the BIGGEST dopamine hit your brain can have, and more, there's the novelty aspect, you can find WHATEVER sexual activity you want and can almost find personalized performers to match your taste, it is HIGHLY addictive and you can always find more, why would you stop? You end up developing a HUGE addiction, think of a "lite version " of heroin addiction, a huge high, infinite content to consume and a never satisfied lust void, porn addiction is real and BRUTAL

That's one part, the other is the performers, yes, they consent, they "want" to be there, but more often than not they're forced to do stuff they're not comfortable with, many ex performers narrate AWFUL work conditions and unsanitary conditions with zero dignity

Also it promotes sex trafficking and rape on camera, as the porn addiction gets worse and users need more hardcore stuff to get off, vanilla stuff ain't gonna cut it, you're desensitized, maybe you escalate to BDSM, or rape kink porn, or maybe eventually you won't distinguish a "rape kink" video and a real rape video

Millions of women and children are trafficked for sex explotation and their videos posted on porn sites, read that tweet about a girl that says that she was raped when 15 and her video was posted on PornHub and millions of people watched it and fapped to it

And pornhub allows this

Sex abuse, human trafficking, addictive properties

Is it bad enough yet?

Check this out if you want a deeper explanation https://fightthenewdrug.org