After svn, git was a breath of fresh air; far easier to use and reason about, not to mention much faster.

I don't think much of your all-in-one solution like fossil - that's a competitor for GitHub (without the bits that make GH good), not git.

I tried to use hg at one point in the early days, and found it much slower than git. Git's low latency for commands made a substantial difference, perceptually. In principle I think git encourages too much attention to things like rebases, which fraudulently rewrite history and lie about how code was written, just so the diff history can look neater. Working code should be the primary artifact, not neat history, and rebases and other rewrites make it too easy to cause chaos with missing or duplicated commits in a team environment. So ideologically, mercurial is a better fit, but that's not enough to make me use it.

Fit is a function of an environment; when we say survival of the fittest, we mean fitness as adapted to an environment. Feature set isn't the only aspect; at this point, the network effects of git are insurmountable without a leap forward in functionality of some kind.

(I think git & hg are just as elegant as one another; to me, the elegance is in the Merkle tree and the conceptual model one needs to operate the history graph.)