Have you tried it?
Parenting in a world where kids face unlimited temptation to consume things that you believe are harmful to them paired with near instance access all over the damn place is pretty hard.
In ever previous era, with every previous vice society has agreed to put at least some barriers in front of children and to do so in a mostly if not perfect way. Most 8 year olds cannot simply go get a case a beer anytime they want, and if they do there is ample opportunity for parents to find out about. You know if your two young child is running with inappropriate people and you either do something or don't.
Same thing with other things like smoking, hazardous materials, etc. The book shop won't let your kid into the adults only section...
but here is the important but, you CAN still let your child take their bicycle and pocket money and go to the c-store, bookstore, etc and get some candy and comics/pokemon cards etc. They can go an interface with the world in a safe way.
Now try this online... At best you get parental controls on the platform, which may or may not reflect what YOU the parent feels is or is not fit for your child, but rather what someone at Meta decided was fine. Things like youtube-kids, ok but nothing stops them from just watching as a guest. Sure you can lock down their phone, but you have control over the library PC, their friend bobby's tablet, etc. Thanks to 'privacy and security' which we all know is really just about DRM you can't implement your own parental controls without entirely breaking the web and apps, and smart devices.
You are left with accepting mega corps get to put whatever they want in front of your kids eyes, infantalizing them entirely and/or never letting them touch anything electronic without your shoulder surfing.
The status quo is an should be treated as unacceptable. The privacy and expression concerns should be the problems to solve rather than reasons to toss our hands up. Anyone just saying 'parent harder' should should get busted in the teeth!