The parent is correct, in theory .eu requires residency or citizenship in order to register a domain[1].
After Brexit holders of .eu domains that did not meet the criteria lost their domains[2].
And the .eu is not the most restrictive ! I am a French citizen but live outside the EU, so I can't get a .fr domain (at least, again, in theory - haven't tried in practice) but I could get a .eu one.