Yup, that's probably why it will mostly be a hobby project supporting a limited number of great writers/publications so that I don't have to think about funding/growth and all the things that are associated with that!
That's definitely one of Medium's strengths and something I'd like to focus on when I find the time. I still have much reading to do about SEO in general.
LaTex, syntax/code was high on my priority-list while initially building my product since I wanted to primarily target technical writers.
I'm currently working on an alternative to Medium. So far it has all the elementary things like a working editor, notes and highlights, a decent commenting system. There are publications too, with teams, submissions etc. User profiles and publications have custom domains, custom CSS for branding. There's also a somewhat half-working Github integration for advanced writers but I'll need to work on it a fair bit to polish the edges. At some point, I'd ideally want to open-source the editor/bloggy bit and have people self-host it and perhaps push their content back to the platform for centralized distribution if they want.
It's still a work in progress and I'm trying to figure out some sort of strategy, especially a content policy around not allowing clickbait and spammy "how to use learn redis in 3 minutes" type articles. I'd probably have to cap the max number of users and publication to a few thousand since I don't have the resources for this to be anything more than a hobby project.
I'm aware of a couple of others working in the same space. Write.as comes to mind, thought I don't think they're doing publications etc.
I was going through a HN "best books" thread recently and found someone recommending "How to Speak How to Listen" by Mortimer J. Adler. I'm about halfway in and there are loads of great tips in it!