Overall this is a good piece, and I'm glad that you highlighted designers and developers working together. Having said that, it still seems a bit one sided, wherein the designer "must" learn more about coding. Developers, in my view, need to learn more about design principles. I wrote about this here, for anyone who is interested.

How learning design can make developers more valuable—and better teammates

I say this having collaborated with developers as a UX designer for both a startup and for a large media organization. When both parties in the collaboration are open to learning from each other, that is ideal. That wasn't always the case. Developers who think that concerns about responsive typography, color, and hierarchy are unimportant so long as their code works are not good partners.