Failed to create importer 'BitmapFontImporter'

Custom content importers have been broken for many years now, and this issue has been reported numerous times in these forums but has never properly been fixed. Can we please fix this issue once and for all?

As an aside, the previous solutions do not work for me (add a reference to …/…/packages/…) since in VS 2022 and .Net Core 6, this packages folder does not exist.