I don't understand this take. If government forces these companies to have age verification and they can't say no, then this can be applied to any of these counter-examples given too; Matrix, IRC, etc. There is no difference between forcing a single entity vs. multiple entities. If the punishment for non-compliance is high, no-one will risk doing it anyway. There is no escape here.
nope, because they can be ran outside of those jurisdictions and they can also be ran essentially anonymously - although that can be challenging depending on the service, but it is possible