I meant more in terms of development. The way git is used most of the time is by having a main branch on GitHub, that contributors clone, work on a feature branch, then make a PR, have QA test it, and merge it. If that cycle is too slow, many times the devs will start complaining because they are "stuck until the branch is merged". Because the assumption is that everybody branches from the main branch.
But git was designed around the email workflow. Instead of a PR, you make a patch (or a group of patches), that you can share with others. For instance, you can share a patch with a colleague from your team, who will review it and incorporate it in their branch before it gets merged into main. That way they are testing it by using it. At some point your changes get merged into the main branch, and your coworkers can just apply their patches on top of it.
We can imagine a workflow with a hierarchy of maintainers: devs at the lower level send patches to their supervisor, who after a while sends them up to their supervisor, up to the main branch.
PRs flatten all that. Devs typically never learn how to deal with patches, and the review process ends up being "rebase on main, run the CI, then I'll skim through your code, I'll complain about some variable names and I'll approve without even pulling your code" (I'm exaggerating a bit, of course).
I think there is a lot of value in learning the git email workflow.
This post (not mine) is about this: https://web.archive.org/web/20170823054920/https://dpc.pw/bl...
And of course SourceHut (https://sourcehut.org/, not mine) is a great forge built around the email workflow.