It's pretty trivial to block access to certain sites or apps. Or better yet, you raise your kids well so that you don't need to rely on technology to keep them away from bad things.
Well that's an inherent problem of having multiple people with custody of a single child.
Ideally a compromise can be reached, but in extreme cases I suppose it could end up with litigation. But still, this is a private dispute, not something that should require outsourcing parenting to the government.
I'll do my best raising my kids well, as you said.