git's purpose is to track change and provide meaningful insights into code written by many different people.

The fact that you can use it to deploy is just a side effect and using git solely because it makes it easier to deploy changes is thoroughly missing the point.

Every large organization I've been in performs a squash merge with the PR description as merge commit summary, because intermediary commits are always noise like "fix tests" and "didn't actually fix, do it now". That's a story not worth reading.