Adams adjusted heavily with dodging and burning, even working to invent a new chemical process to provide more control when developing. He was great at determining exposure for his process as well. A key skill was having a vision for what the image would be after adjusting. Adams talked a lot about this as a top priority of his process.
Contact printing on azo certainly helped!
> It's even more incredible that this was done on paper, which has even less dynamic range than computer screens!
I came here to point this out. You have a pretty high dynamic range in the captured medium, and then you can use the tools you have to darken or lighten portions of the photograph when transferring it to paper.