One thing to note is that these laws (or at least Louisiana's and Virginia's) don't criminalize anything. Instead, they create a private cause of action (meaning that someone can bring a civil lawsuit) for damages that result from underage exposure to pornography or whatever. If I had to guess, it's an attempt to get around any possible First Amendment challenges by a porn site, just as Texas' anti-abortion cause of action laws were intended to get around Roe before it was overturned.
I'm going to be very curious to see how this plays out assuming anyone ever actually sues. It's not clear to me what actual damages could actually be proven, and at the least doing so would be difficult and expensive. Plus, in most states AFAIK, the plaintiff has a responsibility prior to suing to mitigate damages, and failure to do that can hurt a plaintiff's claim (the specifics are going to be entirely situation- and state-specific). It would also be pretty easy, I'd think, for the site to argue some variation of contributory negligence or comparative fault (depending on what the state in question calls it) to at least reduce any award if not eliminate it outright. Come to think of it, this might actually require the site to sue the parent(s) directly, since at least initially, the parents would presumably be suing on behalf of their kid rather than on their own. (This is starting to sound like a bar exam question.)
Finally, even assuming someone wins such a lawsuit, actually collecting is much more difficult when you're dealing with a non-US defendant. It can certainly be done (depending on the country in which they are based), but that too becomes extremely difficult, time-consuming, and expensive.
I'm sure there are parents out there who'd be willing to do this, but I doubt there're that many. Most sites, at least for now, are probably willing to roll the dice on that.
Mike Dunforth is great. I hang out on a discord server associated with his Twitch stream, where he does videos talking about various goings-on in the courts and what-not. Also weekly minecraft.