Trust me, I'm a software developer with more than two decades of experience. Have been dabbling in hardware since the Amiga 500 era. "I have that specific set of skills" that allows me to narrow down a class of issues pretty well - just a lot of component switching in a binary divide and conquer fashion across hardware.

The issue is 1) actually exaggarated in the community, but not without actual substance 2) getting disregarded exactly because of exaggarations. It was a very real thing.

I also happen to have a multi gpu workstation that works flawlessly too