content: Production waste, and heat, mostly. The bigger a chip is, the more likely it is that something goes wrong during production. Which leads to the chip being non functional, or only functional at lower speeds, with less cores, or less memory. Heat is also a problem. Every component of a chip uses electricity, which generates heat. The more components a chip has, the more heat it generates, and the more likely it becomes for those components to get into each others way when it comes to getting the heat out of the chip.