While I agree, I don’t think the language “every operating system provider has to create” means it’s installed if you don’t want it. Parental control software exists for Linux, it’s available from the package manager, and we can opt out of installing it.

I doubt “every operating system” is meant literally. Embedded OSs for specialized hardware (eg, routers, satellites, rockets, missiles, drones, calculators, industrial lasers) aren’t typically meant for children to browse the web. If TempleOS supported networking, it might be in trouble. Viable legislation would probably be restricted to OSs designed to allow children to access content over the internet.

The main thrust of the suggestion is to prefer parental controls over age verification. Better ways to ensure availability of parental controls (like government services to provide the software free) fit that broad idea.

I can make its logic gates do anything I want, as long as it’s not sending CP or malware over the Internet.

That stipulation doesn’t need to be stated. It can be programmed to do anything, and that’s fine. Laws already exist for illegal activity. Anyone who’d fuss the absence of that stipulation lacks credibility.