In truth, Medium’s main product is not a publishing platform, but the promotion of a publishing platform. This promotion brings readers and writers onto the site. This, in turn, generates the usage data that’s valuable to advertisers. Boiled down, Medium is simply marketing in the service of more marketing. It is not a “place for ideas.” It is a place for advertisers. It is, therefore, utterly superfluous.
Medium is a great platform but while the product is great, we the users are the product as well. Our writing and reading behaviors are what they use to sell to advertisers. No doubt, without ads, how can a service be free?
For readers who are into blogging or writing. I would suggest to use Medium as a distribution channel while still keeping a WordPress blog with your own domain. Because you are the platform owner and you have the freedom to choose what you want to do with it.