Apart from the tracking and soft paywall issues that you and some comments mention, there's another problem with sites like Medium and Substack (and Linkedin an

Apart from the tracking and soft paywall issues that you and some comments mention, there's another problem with sites like Medium and Substack (and Linkedin and others, too) Publishing on those sites requires minimal effort. As the userbase grows, those sites attract more and more low-quality creators. Although there are many excellent writers on Medium, there is naturally also an increasing proportion of spam. This flood of low effort content harms the perception of the entire site, so today when we see a Medium.com link perhaps we hesitate to click.