It's absolutely worth taking the time to learn `jj`, for example, but `jj`'s ideas build on top of `git`'s ideas. If you don't know why it's important that commits reference their parents, for example, that's limiting your knowledge of how VCS works in important ways.

A compromise/synthesis: everyone should absolutely learn how git works internally, but not necessarily how to use the git-specific porcelain/tooling/CLI