> The number of people on this planet with the singular knowledge to build a modern processor, from scratch, I would estimate is well under 1,000

I am pretty sure that most EE/CE students at some point or another implement a basic processor on a fpga. That being said, I am not sure how many of them would be able to build a "modern" one.

Yeah the number people who can, by themselves or with a small team, build a modern processor that's half as fast or half as efficient as something AMD put out 10 years ago is so small it's actually probably a negative number. Fabs are really, really, really really really expensive and processors are really hard to design.