[data_acquired]

Oh good god :) Picking up writing from reading the average paper is likely injurious to the health of your future readers. Few papers are well-written and you're likely to unknowingly pick up bad habits from reading the average paper. If your advisor was actively training you in good writing and providing you critical feedback on sentence construction, paragraph organization, the flow of ideas from one section to the next, then sure, you wouldn't really require a class. But I doubt the average advisor has the bandwidth for such feedback, esp. in my field of biology.

In the context where I taught, most students coming into the PhD program had no training in writing whatsoever. The first round of essays that people turned in were typically very poorly written. Most folks really needed the training in my view.

[bonoboTP]

I mean, you wouldn't emulate the average paper though, but the ones from the best labs in your field, the papers that get awards etc.

I think it's actually better to seek writing advice on the Internet (not from randos, but if you're cut out for a PhD you should be able to tell apart crap advice from good ones.) I'm pretty sure it's better than whatever my university could offer as a course.

And just as everywhere, 90% of everything is crap. Perhaps more than 90% of papers are crap and 90% of academics have nothing to say and write terribly to hide it.

[data_acquired]

Fair enough. It does sound like you fall/fell on the more advanced side of the grad student curve though. +1 on 90% of papers having nothing much to say.