I also do both.
I've had two Wordpress blogs for over a decade at randomterrabytes.net and statswithcats.net. One is for my introductory-but-technical statistics articles and the other is for exerything else.
I joined Medium a little over a year ago because I thought I might have access to a wider audience and the platform would do more promotion than Wordpress.
I've found a couple of things. Thw Wordpress editor (the software where you enter your story) is far more capable, and hence, complicated, than the Medium editor. I use a lot of graphics and have found the Medium editor to be barely functional. It's designed for writers who just write text. The formatting capabilities are extremely basic.
I thought Medium would be far better at promotion but that hasn't panned out. Their rules are very complicated, kept secret, and change all the time. Publications are in, then out. You have to get curated (distributed) to get any promotion, but then you can get undistributed. The editors who were doing the curation were all fired. Now they have limited programs. It's a real mess.
The one thing Meium does better than Wordpress is the statistics, although rvrn these are shrouded in secrecy. When does a view become a read? What's a clap worth?
I won't even get into the payment programs.
I can't agree with your conclusion. Both sites take care of all the technical maintence. I've found Wordpress technical support to be far more curteous and helpful. Medium could be good, but it has its quirks, as does Wordpress.