@8051 programmer, nice story... I am EE and also did early embedded work on Intel micros and later went to work for the company.
Intel downfall is multifaceted, but I would simplify it to Intel being 100% focused on maximizing success in vertical integration around proprietary processor. During period of weak competition and high growth in pc, notebook and server it was pretty smooth... But Intel became very lazy and bloated. Anytime Intel tried to enter new market via I eternal growth or acquisition it simply could not generate any staying power. In part, internal competition from internal groups contributed to the demise of anything outside the core. aSG called the problem, Intel's creosote bush... Look it up ... A desert plant that consumes all adjacent resources. One example, powerful TMG / TD didn't help and even sabotaged any silicon projects that needed different process and libraries compared to high speed processor.
This is a vast generalization of what happened and there are many many elements of TBE failure but to me this is what Intel calls ' root cause' analysis. By contrast, look at Microsoft or n India they enter new markets and stick to it until they win. They have a wider product line and much better diversification.