When I started my business I had a previous blog with several topics covered.
Because I self-hosted, I managed to redirect the traffic only for a specific set of posts on the topic to my new business blog where I moved several posts over, getting thousands of visits in my business blog (and converting customers) since day one.
The Ghost blogging platform is open source, and you can self-host if you want (I do).
With Ghost, you can also get their hosted service for a monthly fee and you own your own platform, you have a markdown-based editor with markdown on the left and content on the right.
You can run your own ads, have a fixed top menu that does not go away with scrolling with links to your products and services, etc.
If you are serious about running a business blog, you should definitively self-host. I know Medium has the sharing aspect, but it's not worth it because most of the traffic in blogs in general comes from Google searches and not sharing.
The social sharing traffic is a drop in the ocean for most blogs, it's not worth getting potential paying customers blocked due to a medium paywall popup.