Actually Apple and Google design their own chips but they do not make them, neither does Nvidia, the Taiwan company TSMC makes the chips, in fact they make nearly everybody's chips. About the only company that still designs and manufactures their own chips is Intel. TSMC has promised its customers that it will never design a chip, it will only manufacture them, and by specializing it has learned to be very very good at it. But I agree Nvidia is unlikely to keep its virtual monopoly on AI chips for very long.