I'm surprised this hasn't accelerated so much, considering the availability of the internet, relatively cheap hosting, donation services like Patreon, typesetting software and platforms, etc.
I guess if you wrote a simple PHP webapp on a shared hoster you could get under 10$/m and up to 100k Users per month easily (about 2 users per minute) and 10$/y for the domain. (Probably still under 10$/m total)
I guess a lot of people don't think they can actually host it themselves and it requires some technical skill (you don't find everything as a precooked SaaS on the internet)