Buddy Guy and Robert Cray, like some others you mentioned, are masters of the form. I would never dispute that. However there is a difference between mastering a form and creating and innovating new developments. Those guys are rehashing the glory of the past. Even though they produce new variations, which involve creativity for sure, it is not real authentic adaptation. In the 20's the idiom was continually changing out of a need to express new things. Same with the electric ensemble stuff of the 50's. The need came first and artists filled that need with work that either did the job or failed to do so. I think Buddy Guy's Chess work is remarkable, but now he coasts off of his mastery to accolades that are often uncritical.
As for the white bluesmen you mentioned, I think their innovation was to take those delta roots and bring them into contexts that were amazingly diverse. They were musically aware of Stockhausen, Schoenberg, Cage the Beatles, LSD, and world literature. Page, for example, was highly educated and literate. You can't compare him with a dirt farmer who could not read or write. It is a totally different music for a totally different context, and it was fantastic. Blues-rock is great for what it is, as is country blues and chicago blues, etc. Everything has its place.
As for the white bluesmen you mentioned, I think their innovation was to take those delta roots and bring them into contexts that were amazingly diverse. They were musically aware of Stockhausen, Schoenberg, Cage the Beatles, LSD, and world literature. Page, for example, was highly educated and literate. You can't compare him with a dirt farmer who could not read or write. It is a totally different music for a totally different context, and it was fantastic. Blues-rock is great for what it is, as is country blues and chicago blues, etc. Everything has its place.