This was pretty much my take as well. I have an older CPU, Motherboard and GPU combo before the newer GPU power cables that obviously weren't tested properly and I have no problems with stability.

These guys are running an intensive game on the highest difficulty, while streaming and they probably have a bunch of browser windows and other software running background. Any weakness in the system is going to be revealed.

I had performance issues during that time and I had to restart game every 5 matches. But it takes like a minute to restart the game.