I now haven't used Mercurial in about 8-10 years or so. However, I recall enjoying the workflow a bit more, and I did like how commits were explicitly linked to branches as opposed to branches being effectively pointers to commits - it was nice to find out the original branch of any given commit.

However the killer feature of Git is the ecosystem. I was always having to do lots of custom work to get Mercurial to work with CI providers, whereas Git just worked and had first class support. It was clear after a while that our team would always be outsiders if we continued down that path, and there wasn't enough of a compelling reason to stay with Mercurial.