for its network effect. I got way more followers than I ever had before using different platforms.

I don't, but I had a member in one of our online communities that insisted on using Medium.

Compared to self-hosted solutions, a medium blog had a professional look from the get-go. This was the major reason why said team member wanted Medium.

I don't think open source projects has yet caught up with Medium editor in it's image uploads, YouTube embedding, or the good looking CSS. Gutenberg and Drupal's Paragraphs has made good attempts though.

The new ghost 3.0 release is pretty fancy wrt to the styling and layout defaults.

For various subjective reasons, i've not used medium extensively so i can't compare like for like, but from what i have used it's not significantly better than ghost on the usability/styling front.

For the articles I post there, because I haven't bothered to set up a website to host them, and don't really care enough about the topics covered to do so.

It used to partly be down to discovery too, but since then I've realised that discovery on Medium is basically non existent, and that success there seems to come down to either getting lucky with staff picks or having an existing social media following.

It was because of ease of use, being free, good SEO and readership. I just deleted it yesterday though because of privacy.

I don't(after they retracted the custom domain thing). Now, I host on Ghost :)