Any more recent Nvidia gpu in sli will just obliterate that. Matter of time.
Unlikely tbh. Aside from Port Royal and Time Spy Extreme, literally all 3DMark benchmarks are absolutely dominated by RDNA2 and it's traditional rasterisation strength (and doubly so for the Fire Strike range of benchmarks).
I literally can't get anywhere close to the 6900XT scores with my 3090, and my 3090 is in the top ten for my hardware configuration (3090 & 5900X) for pretty much every benchmark going.
RDNA2 is just really hilariously good at DX11/12.