Yes, pre-built PCs are mostly Intel. Intel is a big ship that takes time to slow down or turn direction. AMD / TSMC lack the capacity to supply a high percentage of the market. So, they are taking market share in the higher end stuff, as margins show, where Intel has been struggling. Oh, I know Intel is going to leap frog in year or three.
However, Buffy and I were talking about folks who are tech, more likely to roll their own.