I think that some of the hardware design folks have been blindsided by AI demand and we haven’t really gotten that next generation AI hardware yet, to the point where buying M5 isn’t going to make sense in a couple of years.
Rumors seem to be that the M7 is the generation that Apple is looking to push AI performance much further.
I’m not sure that Apple anticipated this specific route that computer hardware has gone and I don’t think M5 and previous iterations were really specifically architected for local AI performance, more like they happened to be pretty good at it.