Mainstream economics argues that the market tends toward equilibrium, not that it equilibrates instantly, and that the structure of specific markets controls the speed of that process. Modern semiconductors are fantastically capital intensive, and so respond slowly.
An Intel leveraging their position to under-invest and earn outsize gains from their leadership position in x86 ... would lose business to competitors (like they have been by AMD), innovators (like they are to Nvidia) and substitutes (like they have to Apple Silicon).