>Like, trivially, it's an ASIC, so I can use it to simulate a von Neumann[*] machine

No, that doesn't follow at all. An ASIC doesn't mean a general purpose CPU or FPGA. A chip that only knows how to do, say, video decoding is an example of ASIC. The video chip can't do bitcoin, the bitcoin chip can't do monero. They're not general purpose.