As a reader, I have struggled with the quality of writing here on Medium, in part because Medium's algorithm for my newsfeed leaves much to be desired. Your essay was not in my newsfeed and yet I found you. I'm glad I did.
Anyone can publish on Medium, just as anyone can set up a blog on WordPress or a newsletter on Substack. So, yes, the quality of some "stories" is low given that there's no generally gatekeepers here.
While Medium publications require editors to approve or disapprove submissions, I know that some editors approve with a light hand. However, I've also read where editors worked with writers, giving them one-on-one support the writer might not have gotten elsewhere.
Those writers who bemoan the low quality of writing on Medium either need to just keep looking, as you suggest, or move on. Life is too short.