You guys are too focused on the present to see the possibilities of a 3080Ti card.
First of all, the 3090 is the new Titan. They're not intended as gaming cards but aim for the prosumer market, with the option to play games when not working. The best indication of that is that the 3090 runs slower than a 3080, albeit not by much.
Now, imagine what a 3080Ti could look like: fabbed using TSMC's 7nm process, allowing it to run at 200-300MHz frequencies with the same power consumption, with the extra hardware and 12GB of VRAM. You get a card that will easily be at least 10-15% faster while still leaving the 3090 the memory capacity advantage.
Sure, they could leave the 3090 with a large memory advantage, but depending on the memory on Big Navi it could still leave some to be desired if they come up short. I'm just hoping for a proper improvement over a standard 3080, like the one I saw on the 980 and 980Ti, I've more or less decided to go with a 3080Ti, whatever it might be since it's likely to serve my purpose best.