I've never had discussions about code formatting in PRs, this seems like a made up problem or something that predates my career.
> something that predates my career
That's because everybody uses linters nowadays, which was the original point.
I've made comments if the formatting is egregious enough. This is a "bigger problem" in not-python, languages without significant whitespace. You can truly write some horrifying code that will compile just fine.
These used to happen all the time. In one (otherwise great) programming course in university you would even get points subtracted if you did not follow the lecturer's preferred style.
(I think that in their case it was partially because uniformity made correcting faster.)
Silicon Valley (the TV show) memed about it with its tabs vs spaces bit. It used to be a thing for sure. It has been a good 10 or 15 years since I had such a discussion. Automated linting and formatting tools largely killed it in my experience.
> this seems like a made up problem or something that predates my career
I can believe the latter, and I can assure you this was a Big Deal back in the day. There's a reason Go ships with gofmt, and gofmt was somewhat revolutionary for being a built-in "you gotta do it like this" back in the day.
It's not by accident that tabs vs spaces is one of the stereotypical great debates in programming.