In a space that requires, quite literally, a decade of good product development plus investing a trillion dollars to make a product that can compete with other companies that have already invested a trillion dollars, it's only natural that there be very few competitors in the market, and they're all competing on different things so they can still make a profit [apple only builds for their own products so they can go the console route and make money on the backend; intel/amd do general purpose computing and thus relatively low-margin but wide market-share; nvidia only does GPUs and server stuff because they can specialize in it very well).