As far as I'm concerned, posting any content of value on any platform or service that you don't pay for and don't have a good control over is a bad idea. It doesn't matter if it's Medium or Facebook or Instagram or Quora or anything else. If it's, say, on one of the Facebook properties that puts up barriers for people not registered with them (and thus the content is not easily accessible on the open web), it's a terrible idea.
Those who value their content should (when financially feasible) ideally use paid services or paid hosting where the provider's interests and the publisher's interest are aligned.
Those who value their content should (when financially feasible) ideally use paid services or paid hosting where the provider's interests and the publisher's interest are aligned.