A lot of humans don't currently trust agents to touch VCS today. I also find that my agent tends to be much better about dealing with jj than it is with git.
Culture change is hard.
A lot of humans still don't use git too.
Many do only when they are forced.
And it's much easier for a professional to be forced to use LLMs than jj when it comes to versioning assist (not even comparable in mindshare but the obvious needs to be said sometimes).
So unfortunately I'm afraid jj is not going to achieve critical mass before 99.99% of merges are done by AI which don't need jj.
I'm one of those people. I don't really use jj, but want to give it another try. Think I'd feel more comfortable letting ai mess with jj because of its excellent ability to undo/redo (op log).