This might be an epic task that is very hard to fix but let's document this problem at least in public.
This is one outcome from T113378: Lessons learned from the first Gerrit Cleanup Day.
There seems to be unclear responsibility for some parts of MediaWiki core so nobody looks at its proposed changes in Gerrit.
Related links:
- "New core team?" meeting: Etherpad log from Wikimedia Developer Summit, 2016-01-06 unconference day
- T149533#2956629 from Wikimedia Developer Summit 2017
Internal / non-public WMF page that brought up the topic of WMF's Core maintenance- Old MW Core team page with its responsibilities