For one, if you don't like a project using a freemium service for its documentation, then take it up with the project, not with Medium.
Secondly, documentation isn't free; is it really that unreasonable for projects to want to be funded for the work they're doing? Medium is pretty cheap. If you're running into your Medium limit regularly, why not just subscribe?Complaining that you have to pay $5/mo to access a resource you use a lot, when you're probably paying $50/mo for internet anyway, seems a bit unreasonable.
But that's on the project, not Medium; and if they want to be paid for the work that goes into their documentation, what's the problem?
I mean, seriously, Medium is $5/month, for loads of advertising-free content. Why not just subscribe?