I've actually only seen it used on the right, nearly always by friends or family who constantly read the news, always in a derogatory sense. Was it common on the left at some point?

Yes, it originated there, though I guess it didn't last very long. It's a common rhetorical tactic used by partisans on the right - use the other side's own terminology to describe it, always with a tone of disgust, and repeat it until the sound of it becomes grating. "Social Justice Warrior" was similarly exclusively used by people describing their own political convictions when I first encountered the term.

I'd say both sides make the other side's terminology into epithets. But mostly only the left seems to take it personally and stop using the word. Meanwhile the right will continue to embrace being labelled by what the left treats as epithets. Maybe it has something to do with individualism which is a sort of rebellious mindset on the right.

I just realised an interesting symmetry - The right is more successful at loading the left's own terminology with negative connotations, while the left is more successful at adjusting definitions of shared language. I wonder whether this has something to do with the implicit communication styles of the respective tribes... Any theories?

“Woke” has quickly gone the way of “liberal” and become an insult. It was a stupid word anyway so I don’t mind if it just goes away.

I pity people who use "woke" as an insult.

It’s been a very long time since I have heard somebody use this word in a positive context.