Unless you’re making more than $16 each month (most are not making anywhere close to that) from Medium then you’re just choosing another company to profit off of you. It’s also more work and takes a lot (arguably, depending on your technical comfort level) more time.

Do you own the content that you publish on Medium?

Yes. Everything you publish on Medium, that is rightfully yours, belongs to you and you can republish, delete or choose to convert it into other forms without worrying about anything because Medium gives you the ownership. They have clearly explained this in the Medium terms of service.

Medium (company) might use your content to redistribute, translate or modify, and they need your permission for this. They need licensing for this because of the Medium rule; “You own your content”

Medium is like an ocean in part because it’s so easy and free. There are some really spectacular fish and animals and rare finds and even shipwrecks full of gold and treasure. There is also a metric shit-ton of mediocrity.