I like Medium / Devto because I get way more traffic! I think if you're someone like Dan Abramov or someone with a massive following you can get away with publishing on your own domain and still getting a ton of traffic.
Also, if you self publish for a while and bulid a name for yourself an audience you can probably get a good amount of traffic.
The other thing is the content, whether you own it or not. With Devto it's just markdown so it would be easy to also replicate it on git somewhere just in case!