Honestly, if I had to guess, I would think that it would go the opposite way: That someone with an attraction that is illegal and/or harmful to act on discovers the existence of virtual stuff and thinks, "Here we go, I can act on my feelings in a way that doesn't harm anyone."
The term that p3dos (or MAPs - Minor Attracted Persons) use for this is "Harm Reduction." There was an interview I ran across on youtube with a porn lady, Katie Starling. She runs a website/forum or something where ageplay content creators (some of them VERY extreme) can get together and create that sort of content. It's mostly banned from all the major content sites, like ManyVids, OF, etc. You can't get up there and pretend to be an underage girl or they'll straight ban you. So she made a platform for them. Anyway, her argument is that they also host support groups and such and they want to ween people off CSAM. Her logic being that if you are out there thinking about harming a child, you should have an outlet that is safe and harm-free. So jerking off to a petite 23 year old in pigtails saying she's ten years younger and roleplaying your daughter is a safer way to move through the world, and if that outlet exists, her argument is that some of these people won't consume (or god forbid, create) CSAM.
I don't know which is more likely - a dude gets tired of regular porn, so he gets into JOI porn, then gets into ageplay porn, then eventually escalates to actual CSAM, or the opposite, where there's a p3dofile that is thinking about doing something awful and ends up jerking off to ageplay porn and chills the fuck out.
I'm no psychologist. And obviously I'm here on lewdcorner so I'm not exactly unbiased - I like loli games and I like that fantasy. But I am *not* attracted to real children. It's like the incest thing, too. I have never, ever wanted to fuck my mom or my sister or even my aunts. (though my Uncle Dave's 2nd wife - maybe I guess). But I like the games, the fantasy of the game is taboo and fun and I enjoy it. I have been playing these games for years and I have not escalated.
In fact, honestly, the kind of games and porn I consume now that I'm older (in my 40s) is a lot tamer (and less frequent) than the stuff I consumed in my 20s and 30s. I guess as I got older, maybe my libido slowed down a little bit, or I'm just busier. I find myself really enjoying games like Whoremonger NTE now more than the games where you play a son with a hot mom.