This is what I came here to say. Assuming the team is working from JIRA or something, put the ticket number in the commit message. The ticket itself is where your “why” goes.
I think that breaks the thing that people want which is being able to `git commit -m "Fix #234353"` without a body at all.
`git commit -m "Fix actual words that humans read" -m "Fixes: #234353"`
You could probably script this based on branch if you're one of those people who names branches after ticket numbers.
But my actual advice is that I think -m is a bad pattern that leads to bad commit messages, and omitting the message argument opens your EDITOR, and you should use that.