Wow this is amazing stuff. I worked at Intel from 1997-2000. When I started, the Pentium 2 had recently released (this was peak ‘bunny suit’ era). It used the “Slot 1” design instead of ball-grid-array or pin-array for the CPU for 2 reasons – 1) getting the cache and CPU proper on the same die (they resided on separate dice at the time and were joined on the slot cartridge IIRC) and 2) creating a proprietary interface that could be patented so AMD chips couldn’t use the same motherboard (AMD came out with “Slot A”).
It was seeing the radical design of the AMD K6 that led to a side project that turned into the “Core” series of processors, and ended the superscalar Pentium IV line (that and the high power usage of the IV and the decreasing value of pipelining). Yay for competition!