Pipewire did some heavy spamming . Lots of unused data were detected by journal --verify. Clean-up resulted in deletion of some hundred files:
erlangen:~ # journalctl --vacuum-size 100M
Vacuuming done, freed 0B of archived journals from /var/log/journal.
Vacuuming done, freed 0B of archived journals from /run/log/journal.
Deleted archived journal /var/log/journal/94f3af277bac4a8eb57da425c9677379/user-1004@d8e0006754b747b7926bbba34d7fb0f4-0000000000292a22-0005ffadb2a4329d.journal (4.1M).
...
Deleted archived journal /var/log/journal/94f3af277bac4a8eb57da425c9677379/user-1000@6f7ef31b2e4c44138638df81bae85c07-00000000004828a0-0005ffdd7ec2745e.journal (74.3M).
Vacuuming done, freed 1.2G of archived journals from /var/log/journal/94f3af277bac4a8eb57da425c9677379.
erlangen:~ #
Journal is now great again:
erlangen:~ # journalctl --verify
PASS: /var/log/journal/94f3af277bac4a8eb57da425c9677379/system.journal
PASS: /var/log/journal/94f3af277bac4a8eb57da425c9677379/system@f832dd6b45614c25ad0b7155dc59b250-00000000004828a1-0005ffdd7ec62e1e.journal
PASS: /var/log/journal/94f3af277bac4a8eb57da425c9677379/user-1000.journal
PASS: /var/log/journal/94f3af277bac4a8eb57da425c9677379/user-1005.journal
erlangen:~ #
erlangen:~ # journalctl --disk-usage
Archived and active journals take up 35.5M in the file system.
erlangen:~ #