They once again require developers to change publishing workflows.

And they made the changes without providing an official Gradle plugin:
https://central.sonatype.org/publish/publish-portal-gradle/

There is simply no free time to retest Maven changes for the umpteenth time.

If anyone has free time to experiment with Maven, feel free to do so.

No motivation here, we find it better to just compile our own sources. Hopefully one day someone will trip over the Jitpack again and thus build motivation.

Hopefully (just guessing) this is only a temporary hiccup, caused by increased security, until a new guide or tools come up. There is no viable alternative, after all.
Uploading manually isn't an option? New versions come out quite infrequently.

Releases were done manually, snapshots were done automatically.
Now everything is broken because they require new procedures...

Anyway, users use JitPack for many libraries without problems.

Releases were done manually, snapshots were done automatically. Now everything is broken because they require new procedures...

Anyway, users use JitPack for many libraries without problems.

full agree !

If someone comes with a working blueprint how to make it work again: this very welcome.
But I don't waste my time here (again)