A big issue is that sticking an FPGA onto the CPU die itself doesn't really make sense. Those are some really expensive transistors, and you're essentially wast

A big issue is that sticking an FPGA onto the CPU die itself doesn't really make sense. Those are some really expensive transistors, and you're essentially wasting them when they are not being used for cores or cache. Besides, you'd be spending significant amounts of money building a niche product. It would be a lot more viable to use a chiplet approach: bake the FPGAs on a slightly-cheaper node, and just glue them right next to the CPU itself. Unfortunately Intel is still miles behind AMD when it comes to chiplets, and their tech is only just now barely starting to ship.