Argh, how annoying!
I've only got 8 articles on Vocal. I was going to get into the habit of reposting my longer Medium articles to Vocal, but then I had one rejected. It had been previously accepted into a Medium publication, and had been thoroughly checked. But Vocal said it had grammar and formatting errors, but didn't give any further details. So I thought, "Well, sod you then!"
I've just realised, one way to view Vocal is to imagine that it's a Medium publication. If a Medium publication paid so little for reads, was more difficult to use than other publications, and rejected articles without providing details, would you continue submitting to that publication? Probably not.
I've got $15.09 in my Vocal account, but why should I bother continuing? I don't want to get carried away by the sunk cost fallacy.
The time I would spend submitting articles to Vocal I could spend writing and editing new content for Medium.