Surely you'll be able to tell who's YOLOing commits without allowing junk into your repo that you'll have to clean up (and it almost certainly be you doing it, not that other person).

DS_Store files are just annoying, but I've seen whole bin and obj directories, various IDE directories, and all kinds of other stuff committed by people who only know git basics. I've spent way more effort over time cleaning up than I have on adding a comprehensive gitignore file.

It takes practically no effort to include common exclude patterns and avoid all that. Personally, I just grab a gitignore file from GitHub and make a few tweaks here and there:

https://github.com/github/gitignore/