When I was in Scotland, I purposely brought an old iPhone that was passed down to me with an EU account to see if Apple will show this prompt in Settings. Nothing ever appeared in the Settings, only the Apple prompt urging you to set up Apple Pay.
Interestingly, when I signed in to Instagram account I only use for our class group chats (to which I rarely write messages because of CC1.0 in force) and had my VPN set to London, no age verification prompt ever appeared. Tbh it was before the Meta settlement, but still.
So yeah, it's overblown to high hell.