There's quite a lot of mileage in what this guy says, and the "content behind walled garden" thing pisses us all off (I'm a non-Facebooker for All The Usual Reasons and have the same response whenever I see stuff "published" there). But: noone seems to have mentioned the fact that you can publish on WordPress and use the Medium plugin to copublish to Medium. It deals with the whole canonical content / SEO thing, you…
If someone can find your work on medium, why would the bother to find your site and read it there instead?
https://medium.com/@w00t/the-2018-burning-man-ultramarathon-...
Has a canonical tag pointing here: https://johnvantine.com/2018-burning-man-50k-my-first-ultram...
When I search for a snippet of text from the article, the one on johnvantine.com ranks.
And you're leveraging the community on Medium, too, so there's some discovery that can happen on that end. Best of both worlds IMO.