To the extent that Medium has used on-staff professional writers from real world magazines, I would agree that they have some "top-notch" writing.
But there are still plenty of articles that are chosen because they meet curation standards that are flawed.
How else can we explain such travesties of curation as:
• The latest Trump press release disguised as a curated Medium article
• An article published in Zora where some ignorant first-time voter tells us why there's is no difference between Biden and Trump
• Articles by mega popular self help "gurus" who push their version of The Laws of Attraction as if they were scientific
If you want to define "top-notch" as popular or money-making, I can't argue. But if great writing is reduced to subject matter that you would find in a direct mail piece selling you on the virtues of the miracle product du jour, at least explain to your readers how the definition has changed.