I don't think its anything about free speech and other social media platforms. I think its about a revival of the old blogosphere--particularly of those writers

I don't think its anything about free speech and other social media platforms. I think its about a revival of the old blogosphere--particularly of those writers who found success there and made writing their career--with the added incentive that monetizing it doesn't require putting a whole bunch of shady ads on your site, or keeping an infrequently pinged tip jar. Writers like Noah Smith moved away from their blog to writing for newspapers and magazines because its how they make their living. They moved to Substack because they probably felt it gave them more control over their careers.