I wonder if customers really want custom chips or just cheaper ones. Many of these custom AI chips are slower than flagship GPUs so presumably a cut-down GPU at a lower price would be just as good.
But on the other hand the software stack is very mature and they are heavily amortized by the huge volume, so its kinda hard to argue with. In fact its so good that Nvidia can charge outrageous prices for the L40, A10 and such and then turn around and sell the exact same dies to consumers (with less memory).