That would basically be a VPN service. One could argue that since we have these roadblocks, an unencrypted version of it could have its uses.
On the other hand you would create inefficient routes just because some countries are overwhelmed with creating digital legislation. I think the real smart solution is to route around these people and keep them far away from influence in political decisions. Simple and clean.
If that isn't possible, a solution like that might work, but only so long as the majority of countries don't legislate similar roadblocks.
I prefer facial recognition. Probably good that there isn't a popular face-spoofer app, since it would put attention to the efficiency of these verifications.
Credit card info is a bad solution. In many countries they still are rare and it would very likely exclude as much adults as children.
The real answer is that while we should expect children to be online, it is the responsibility of the parents to moderate their usage. Add a standard header to every http request to support filter solutions. That is the only viable solution that is of a technical nature.
The whole ZKP idea is futile, no model works if you also have connection information, which states tend to save too.
Anonymous internet usage is pretty awesome. For adults and kids for that matter. And that doesn't change because there are also bad advertisers that practically can identify and track you. If you want to protect kids, have those be imprisoned first. Strong opinion, I know, but also the correct one.
Software need to interface almost all parts and electronics in a vehicle. Since car makers outsourced these parts, interfacing them took a lot of work. Here manufacturers like Tesla were clearly at an advantage since they controlled all components.
That is a nightmare situation for software that already started later in the development process.
The problem is that there wasn't a correction of these business policies. It still is the same as before, engineering talent gets outsourced and software and more frequently also hardware parts is something that Germany despises completely by now. You are in sales or legal, anything else is secondary.