What an utterly baffling take on this. What does "On paper, the RX 6800 XT should pull ahead from Nvidia." even mean? Do GPUs from different brands have on-paper specification that can be compared to give a realistic performance estimates? No, they don't. TFlops aren't comparable across architectures, VRAM amounts only matter when there's not enough, etc., etc. AMD's marketing said the 6800 XT matched or beat the RTX 3080, which was slightly optimistic, as they are more typically tied. Calling this an unimpressive showing ... how? This is AMD's first competitive high-end GPU in five years. Is it impressive? That's debatable. At the very least it's pretty damn good. Is it "unimpressive"? Not by any sensible measure. Catching up to Nvidia's massive lead in both absolute performance and power efficiency (where AMD is now unequivocally ahead) is very impressive considering where AMD started out from a couple of years back. Most people thought this would never happen.
If Nvidia is postponing the 3080 Ti because of the 6800 series' performance, it's not because they were unimpressive, but because AMD didn't actually deliver a better value proposition or markedly better absolute performance, both of which would have pretty much necessitated a response from Nvidia. Instead they are now quite evenly matched, meaning Nvidia can wait it out for a while yet, and keep raking in cash from existing models rather than spending a ton on creating a new SKU with little going for it.