I haven't heard a pianist play #6 or #7 better than Richter, although I find his #6 hard to listen to. I think his best live recordings may be better than his studio recordings, simply because he hated recording studios and needed an audience to become energized. I like the live version of #7 better than the studio. I don't have a live #6.
I think it's dangerous to allow biographical details to intrude on our interaction with compositions/performances. Prokofiev could have called #6 the Mad Hatter sonata, or something even more off the wall. For me, it's the music that matters. Of course, some might argue that programmatic music truly does deliver a narrative. Peter and the Wolf is a good example of programmatic music. But, I don't hear anything about war in Prokofiev's sonatas, personally. I listened to them before I knew about his "war cycle", and to me it's just as artificial as Scriabin's "state of soul" for his 3rd sonata, and the "white mass/black mass" labels for 7 and 9. It seems to me that to box in such pieces diminishes them. Perhaps Prokofiev was trying to make his music safer politically?