This is a common misconception. My highest earning article “about medium” generated less than $150.
My highest earning article ever was about dating and relationships and has earned over $1700.
I wrote that one with less than 100 followers.
Ultimately, I think it comes down to what your purpose and intention is as a blogger.
Some people just want to write and not be bothered with tech fuss, SEO, and all the stuff that comes with owning and growing aWordPress site.
Medium and Substack are where it’s at in terms of quick results, idea validation, and ease of use.