How would I start learning again the first incarnation of any interesting tech?
I wouldn't.
I would wait for Angular's replacement lib, same as I would wait for React's eventual successor. Or I'd write one.
Read the source, see what they do and why, make your own.
I personally can't handle, can't grapple with that tool-chain. Babel, ES7, webpack, gulp, oh my. All that, and none of it has anything to do with your project requirements, code architecture, or even Javascript (as it is known around the world in it's current form, that is ES2015).
Make your own, learn from the process. Read the code that makes React work in it's current form.
See what others did with React, learn from that.