> However, the "bazaar" is also a bit of a myth in this regard. I'm not really aware of any open source projects where I can go submit a PR without talking to anybody and have the expectation that it'll be merged without discussion.

I am aware of one, but an important one: ZeroMQ. Thanks to the late Pieter Hintjens, this project has C4 model. I have not seen any other project where I submitted a PR and maintainer accepted it less than half-hour later, no questions asked. And it works wonderfully; ZeroMQ is live and well.