Self-hosting doesn't solve the biggest problem of blogging - which is that nobody will read your work.I started blogging in 1999 (and sadly there are the Wayback Machine archives to prove how juvenile I was!) and it was either self host or use Blogger.
Discoverability was pretty interesting. Most blogs' traffic didn't come from search engines (Google existed but it was pretty much geeks only) or platforms, but from other blogs whether by being referenced in a post, via a sidebar link, or via a webring or similar device. Getting over 100 visitors a day to your blog would be a big deal! Getting other bloggers' attention via linking to them was a big part of things or leaving comments on their blog. These things barely move the needle anymore.
While I have a lot of nostalgia for those days, I think there's actually a lot of other ways to be discovered now. Sites like Hacker News, Reddit, Lobsters, Designer News, etc. provide opportunities to be found within various sub-communities. Most people have Facebook, Twitter, LinkedIn and other social profiles on which they can share their links, often findable via hashtags people are monitoring. There are 1001 email newsletters that are always seeking out interesting things to link to.
So, I dunno, is discovery really a problem nowadays? I don't think it is, but maybe I'm too "in the game" to see the problems people are having with it. If anything, I think there's just too much to do nowadays and we're really competing with there being 100x more people online than 20 years ago.