There have been dozens of articles coming out over the past several years detailing how Medium is no longer a great home for the aspiring writer/blogger (largest of reasons is due to their paywall). I fully agree with this.
I used to be an occasional blogger, but had some okay traffic (a few posts took off), but definitely not a name for myself where I could take people with me to my own site. What I liked about Medium was their discoverability, shifting to my blog I believe will lose that discoverability.
Are there other platforms or other ways to get organic readership?
I think the main issue now that is really flooding out creative writing as well as other types of creator communities (I make music for film @ruffandtuffrecordings - a new account mind you) is that everyone is grinding individually than creating partnerships. While everyone is quitting their jobs to become a creator, they are finding they have to do every aspect a corporations would normally hire for and then quickly burning out after a deep investment in time and gear.
It's probably better to partner with people who share your subject matter interest and to form a team of people and then start a dedicated web site that you use social media as a pointer thereto... That way your content also is not under risk of immediate loss in most cases if you pay your bills on time.
That being said, where to go also probably depends most on your intended subject matter.