I actually did a new build in Q4 2019/Q1 2020 and spent almost 2K € without the GPU. ROG Strix Helios case, i9 9900KF, Maximis XI Hero Wifi, ROG Strix RGB 360 AIO, 1TB 970 Pro, 32 GB TridentZ Royal.. Now the fun fact: I'm still running a GTX 970, lol. And yes, I did buy a premium PSU (ROG Thor 850P). Cmon, my CPU draws up to 340 Watts (!) during a P95 stress run at 5.1 GHz, maybe ASUS et. al. need to introduce a new CPU PWR connector?
So if I was forced to replace the PSU for an Ampere card to work I would seriously consider AMD. Because guess what? It would still be waay faster than my GTX 970 😁