Agreed. I've done a fair amount of reworking signal processing algorithms to run on GPU/TPU, and it's a different beast. You often have to really rebuild the algorithm from the ground up to take advantage of parallelization. But often you /can/ rework the algorithm, and end up with much higher throughput than the crusty old serial algorithm: there's typically nothing fundamentally stopping you from finding a good implementation, just that the original devs were working in the 70s and hasn't thought that far ahead.