Back in the 90s, my home computer was an Acorn Archimedes. It had on it a piece of software called ArcFS, which allowed you to create compressed archives, a bit like zip files.
Unlike zip files, they could be mounted as a disk, a bit like dmg files on a Mac.
Unlike dmg files, they were compressed and writable.
If we could do this in the 90s, why can't we do this now? Today I use a Mac, and while I can create compressed disk images, they are not writable. Conversely, writable disk images are not compressed.
What is today's equivalent of ArcFS, and why isn't it more common?