We forgot to update the tooltip when the default keyserver was removed in gpg 2.5.3. This has already been fixed in the meantime. Sorry for the inconvenience!

keys.openpgp.org has two problems: a) it is a centralized service due to the requirement to confirm mail addresses. b) For non-confirmed keys it returns broken OpenPGP keys (ie. without a user id and thus without important information). For these reasons and the general problems with the keyserver-(networks) there is no more default.

I talked with @ebo and we will consider to have a default again but limit that one to fingerprint only requests. Thus they can be used to get keys corresponding to a signature and also - more important - to retrieve revocations.

Ceterum censeo keyserver shall not allow to search by mail address. (Because it lures user to consider that identity as confirmed.)

Thank you very much for yours answers, explanations and effort!!!

b) For non-confirmed keys it returns broken OpenPGP keys (ie. without a user id and thus without important information)

Small nitpick: This is indeed not compatible with RFC4880 or LibrePGP, but it is compatible with RFC9580 and thus OpenPGP. It is indeed an annoying limitation that important information like key flags and expiration is tied to user ids. Alas.

This has been specified in 1997 by PGP 5 for a good reason. We talked often enough about this and it does not help to repeat your ideas over and over again. RFC9580 specifies a different protocol than OpenPGP as specified by RFC2440 and RFC4880 but alas grabbed the name OpenPGP for this.