Well yes, if you constrain the solution set to satisfy "requires no additional software to learn" then you'll end up with the status quo solution.

One thing I've always been concerned about when negotiating a legal agreement is how I verify that the tracked changes actually track every change. Because Word lets the user decide which changes to track, I'm always reading the untracked sections as well to confirm that no other changes were sneakily introduced. That's something that git addresses well. Does Word have a solution there? If not, does that ever concern you?