Glad you got through COVID OK Scott.
Yes, I am sure there probably is a fair bit of plagiarism going on around Medium. There is a site I am a Moderator on and we caught a plagiarist there, but on that site, money wasn't even involved, so I guess the person just wanted to sound smarter than she was by wholesale copying and pasting other people's work and passing it off as her own words. A double shame, since with a little more effort, she could have written fine stuff on her own.
For those of us who do put more than a little effort into composing something, and carefully placing hyperlinks for quotes, it is quite infuriating that others play the shortcut game. Glad you caught one of em.