It's also dying [1]. Git's the only version control system that's got legs [2].
[1] https://trends.google.com/trends/explore?date=all&q=%2Fm%2F0...
[2] https://trends.google.com/trends/explore?date=all&q=%2Fm%2F0...
[1] https://trends.google.com/trends/explore?date=all&q=%2Fm%2F0...
[2] https://trends.google.com/trends/explore?date=all&q=%2Fm%2F0...
Or perhaps they're reflecting GitHub's dominance in the forge space and the fact that they only offer git, so a whole lot of people are more-or-less forced to learn something about git, so searches...
Or perhaps they're reflecting something about hg users preferring other search-engines than Google...
Drawing any sort of conclusive correlation between those Google search trends and actual usage or desire to use one or other distributed VCS is a fool's game.
I'm well aware that everything is git.
This doesn't mean that everything should be git.
Projects like pijul interest me, since they work in a fundamentally different way. Pijul is a "nicer" version of darcs. Git killed darcs not by being nicer but by being faster, and pijul is also faster than darcs, so maybe there's hope ;)
(Of course, most of git's momentum came from huge projects using it, like Linux and Xorg; yet being huge is precisely what forced those projects to favour speed at the cost of "niceness". If a "nice" system existed that was fast enough to handle Linux, Torvalds would probably never have written git).