Well, in Spain you can use your eID directly: https://github.com/OpenSC/OpenSC/wiki/DNIe-%28OpenDNIe%29#up...

And you can get a standard X.509v3 certificate from the FNMT (https://www.fnmt.es/en/ceres), or other agencies, which identifies you online for government purposes.

You can do it in many (all?) of the EU, I think, since the ID card can be used to produce a cryptographic signature.

It's not a GPG signature, but that would be an easy ramp to GPG signatures.

These days though I think GPG is of dubious utility, you could just as well use your ID to sign stuff and stop at that.