Don't worry, most likely your children will come across the normal sorts of bad people - cheating partners, bullying peers, abusive bosses, rude customers, lying beggars, maybe robbers and thieves. It's fortunately unlikely they'll meet a guy who is outspoken about his opinion that scientifically capturing people's attention to get them addicted to screens is morally much worse than showing them "penis into vagina episode 74786". We don't want their innocent minds to be poisoned with ideas that question the status quo.
Honestly if internet porn were "penis into vagina episode 74786" I'd have no problem with my kids who are old enough to desire it, to watch it. The problem is that all internet porn I've seen demonstrates undesirable behaviours and attitudes towards sex and towards their partners. Hitting, degradation, homosexuality, sex between family members, harmful body modifications, verbal abuse, etc, are on the front page of every porn site I've looked at. I honestly do not understand how this is supposed to be stimulating.
I have no problem with my kids watching a couple progress from kissing to foreplay to passion, if those kids already have the hormonal desires to experience these acts. But contemporary websites teach that violence is an integral part of sex - and I do not want my children learning this.