The reason SLI is not needed anymore is because of NVlink and a PCIe bus that is fast enough and has a high enough bandwidth to not require direct GPU links via SLI anymore.
The reason why NVlink is a ‘thing’ - as was SLI - is because it can share GPU load over multiple cards without the application having to be written specifically to take advantage of multiple GPUs.
Without , it or something similar, discreet GPUs are just that and software has to be written to take advantage of them. That is very difficult for ‘lots of reasons’ - FS2020 is not.
Getting tiresome now. You can keep believing what you want, doesn’t change the facts. Bye.