I am (was) a git expert. I’ve written a git implementation. I’ve used it since shortly after it was first announced.
Git has lots of sharp edges that can get hairy or at least tedious really rapidly. You have to keep a ton of random arcana in working memory at all times. And a bunch of really useful, lovely workflows are so much of a pain in the ass that you don’t even conceive of doing them.
^^^ This aspect of the arcana one is required to keep in working memory is an issue that's glossed over far too frequently. I understand that git is a developer focused tool, but requiring a user to keep a constant mental burden in working memory completely bars non-developers from using git in any legitimate way.
I'm not a welder or a metalworker, but I do know how to weld. I use a welder a handful of times per year when I need/want to. Welding is dangerous, and achieving excellence is a difficult and long road. But I can use the same tools as a pro and still get a few pieces of metal stuck together without having to relearn and restudy the whole system each time something goes wrong.
I haven't used jj in anger yet, but I think it might at least be approaching that style of developer tool.
Git has lots of sharp edges that can get hairy or at least tedious really rapidly. You have to keep a ton of random arcana in working memory at all times. And a bunch of really useful, lovely workflows are so much of a pain in the ass that you don’t even conceive of doing them.
I learned jj in one day and never went back.