I mostly agree with you, but DotA plus is a shift towards subtly pay-to-win features. It's always surprising when a subscription lapses and I find out something is a DotA plus feature and not just part of the game.
Teaching is not unfair in my book, and worth money so I find it a very well balanced paid feature.
I played LOL before, and their rune and pick system is definitely pay to win.
All in all, given the size of dota, I'm actually amazed that so much of it is free. I played it years before spending a cent, and wondered how they could be sustainable.
ranked roles