Same story for us, started with mercurial many years ago, eventually the tooling around git and just "using the standard" was too big to ignore and we migrated

Same story for us, started with mercurial many years ago, eventually the tooling around git and just "using the standard" was too big to ignore and we migrated along with a bunch of other CI/CD and DevX improvements. Mercurial was cool, but lacking support meant little things like Jenkins having to "pull" 3x instead of 1x for git natively along with many of these little things meant just using git, generally saved us a bunch of work.