We already had the solution: a decentralized web. But do note that the author used 'medium' rather than to use his own platform and so effectively adds to the value of the medium content-silo.
If not, I'm afraid it's a non-starter. The centralized solutions are winning precisely because the average user just wants to get their signal out; they don't want to be forced to become even an amateur web admin to do it. So long as that's true, you'll find an ecosystem of dedicated individuals and small-count co-ops outside the centralized web platforms, but they'll never become large enough to draw consumer eyeballs away from those platforms.
1) Sysadmining is still hard, thankless, and tedious enough (outside the ecosystem of services that are paying sysadmins to do the heavy-lifting for the end-user) that you're looking at a very select clientele, even among the people who have become sufficiently fed up with the status quo to want to dive into that space. I'm capable of hosting my own blog, but I host it on Blogger because I don't want to deal with having to security-patch my tool of choice every week. Any popular toolchain monoculture is a target for security attacks, and any popular toolchain heteroculture (i.e. "tool that is flexible enough that no two installations look alike enough to allow for security attacks") introduces complications that diminish the adoption rate of the tool. The development of excellent tools freely distributed and improved is not at all a given; the bar to success is extremely high, even if someone comes along to foot the bill (which would be necessary, because if we could expect those tools to spring up for free, the web is old enough that we'd have already seen it happen).
2) Any small co-op that is successful enough either becomes a Facebook or gets bought by a Facebook. Blogger used to be independent. So was Tumblr. So was Livejournal. The monocultures have the money to acquire real competition, and it's hoping too much to pretend the central human owners of such co-ops (or even the entire co-op, if it really is structured as a cooperative) won't just sell the farm for a half-million dollars.
So I don't see independent blogs ever becoming more than a fringe exercise on the modern web (hell, even the original author's reference to Blogger is a service fully owned and operated by Google, which can at a whim change what content is allowed on that network [https://www.yahoo.com/tech/s/googles-blogger-drops-plan-bloc...).