ClearCase is wonderful if you fit the use case, which is a sizable team on a fast LAN.
It's great being able to change a ClearCase config file to choose a different branch of code for just a few files or directories, then instantly get that branch active for just those specific files.
Basically the usual ones that end up with copying the modified files to a temporary directory and doing a fresh clone followed by a manual merge and commit, because someone messed up their local repository while trying out some git command beyond clone/pull/push/checkout/commit, and now cannot push without messing everyone's else.
Have you ever worked with Rational ClearCase? It's a true horror show.