How many of the large systems in the world (civil infrastructure, bureaucracies, the internet, etc) don't involve a great deal of repurposing previously present systems for purposes beyond their original design intent? I don't think we're guaranteed to be stuck with hallucinating AI embedded in everything, but if something gets popular enough to work its way into a lot of tech stacks, it can easily persist well beyond the point where anyone designing things from the ground up would include it simply because it was already there.