Heh, I guess this shows my corporate software dev experience. Whenever I've taught git workflows it was always paired with a work ticketing system where any changes you were making were ideally all one single set of changes. If you need a feature or bug fix someone else was doing that was being done on another branch which you could pull into your code early and for tracking purposes we always made sure the other person merged into main first. The only time I've seen per line manipulation with git was when someone made a ton of changes in a file and wanted to revert a handful of lines.

Everything else you mentioned I've had a web git host like gitlab or bitbucket for, but I kinda put that more into peer review workflow than git itself