I am going to disagree with Ev here.

While Medium is a great platform, there are no long-term guarantees here. They cannot promise in 5 years from now your IP will be safe and accessible. They cannot promise they will not make changes to their experience, which might impact the viewership of your content.

The fact of the matter is if your content is only on Medium you really don't have control over your content experience. Think optimizing your SEO efforts, think managing your community the way you want to, the look and feel that you want to create to support your content. And then we have the branding conversation. Come to my website, MyBrand.com vs. find me on Medium along with other writers.

Whereas if you have your own site, you have an experience you can own and then leverage an aggregation strategy to push your content to places such as Medium or LinkedIn Pulse to help extend that reach. Then if platforms change their TOS or their experience, which does happen fairly frequently, you can choose whether to continue to use those services without much of an impact on your core experience.

Even if you don’t have a lot of traffic to your site, you still remain in control of your IP/content and experience.