I like this system in general, but I don't understand why scaling the number of repos is treated as a pinch point? Are there git hosts that struggle with the number of repos hosted in particular? (I don't think the "Motivation" section answers this, either.)
There are many reasons not to do this, perhaps this scratches away at one of them.
It’s unlikely any Git providers struggle with the number of repos they're hosting, but most are larger companies.
Currently, we're a bootstrapped team of 2. I think our approach changes the kind of product we can build as a small team.
Unless, of course, your product is infinite git repos with cf workers.
You can still sync to a platform like GitHub or BitBucket after all users close their tabs.
A long time ago, I looked into using isomorphic-git with lightning-fs to build light note-taking app in the browser: pull your markdown files in, edit them in a rich-text-editor a la Notion, stage and then commit changes back using git.