Database cache backend garbage collection does not work with permanent entries

I stumbled upon this issue almost 10 years later and it is not resolved by #2526150.
DatabaseBackend::garbageCollection still excludes entries marked as permanent from being deleted: https://git.drupalcode.org/project/drupal/-/blob/11.x/core/lib/Drupal/Co...

I'm reopening this to determine whether this is expected behaviour or something we have to address.
For me, this was a surprise as https://www.drupal.org/node/2891281 → doesn't mention permanent items being kept.

Nevermind... I got mislead by a failing query to check the size of my cache tables and then misunderstood the implementation. Closing as duplicate again.