You make good points and I agree. I would say though that it's not that Medium has too much content but that it has too much fluff that's devoid of substantive content. Medium still, after all these years, hasn't grasped that their path to success requires them to embrace serious content readers can't get elsewhere online. The platform is instead geared toward quantity of things to read and the staff is afraid to promote any serious, deep content that might challenge and scare away readers. Medium still hasn't sufficiently let go of the social media model that fluff is the way to go.
What you say about publications is spot on. I ignore publications for that reason. Medium has outsourced the role of curation to publications (the labor) and that's clearly not working because most of the publication editors are untrained in publishing or content-management.
Anyway, I have heard you. Alas, Medium's staff will ignore you or just gaslight you. But what you say is correct and many of us long-time members and friends of Medium agree with you.
You may be interested in what I wrote recently, referencing an older article.