Well then, let’s call it what we want SLI in 2 or 3 graphics cards, MultiGPU, etc. We already had this problem 20 years ago when we realised that we couldn’t increase the clock frequency of the CPU. It was clear to me long before that multi-CPU motherboards would disappear (yes I know they are still there ;-)) and the cores would be integrated into one housing.
Of course, even two old gtx1070s can’t compare to what a 3080 or 3090 can render. Although I was amazed at the performance of the gtx1070 when you run it with a current high-end CPU. So the current high-end graphics cards can definitely do a bit more if we had even faster CPUs.
In short, if 4k 8k monitors or like the Pimax 2x4K and soon 2x6K are offered, I also want a graphics card that can handle that or the possibility to handle multiple cards at the same time.
My PC has everything that is currently possible and my Pimax 8Kx runs, let’s say, pretty well. But far from 100%.
Note: if someone had told me 5 years ago that I would be able to fly in a flight simulator like this today, I would only have had a thin smile on my face.
If I had the performance of a 3080TI or 3090 for the left and right monitor separately, the result would probably be to my complete satisfaction.
And why should Nvidia be responsible for that. Regardless of whether VR or multi-monitor operation. Why should the Fs2020 not support 2 graphics cards. No matter what SLI or anything else. If I have several CPU cores in which synchronised, independent tasks run, according to Toyota 
it should be possible in “this day and age”.
Microsoft’s flight simulator has always been a challenge for the hardware, but never has the visibility been so good. So the hardware has already caught up a lot. 
Happy flying!
And to the beloved developer team: With the FS2020 as Game of the Year, you have already shown what is possible. But as far as hardware support is concerned, old versions were already further ahead. So be trendsetters there, too.
Not even my old Force Feedback II from Micrsoft is supported and although there is a setting for it: There is no feedback in the fingers. :’’’-(