I am always amazed that keyboards still do this. We have scanning matrices because back when I was a new engineer pins on a microprocessor were both expensive (larger packages) and they required more gates in the CPU (more expensive CPU) or chip doing the scanning. Today transistors are free and surface mount BGA packages can put down a lot of pads pretty simply[1]. So your typical 104 key keyboard could actually have 104 actual wires that the CPU scanned. And even if you don't want to put down a 144 ball BGA (that is only 12 balls by 12 balls, logic is fast enough that you could connect all of the keys to a bunch of serial shift registers, and scan a complete bitstream of all keys 1000 times a second. Easily matching the reaction times of humans.
So where is that keyboard?
Just to be crisp here, an STM32F429 can have 135 digital I/Os in the 208 quad flat pack. It also has a megabyte of flash and 192K of RAM. It also has a USB Phy built right in so you can just wire it up to a USB connector. Its $8 in 1K quantities in that package. So parts : chip, PC board, 120 or so switches and plastic case and key caps. Sure its more expensive than the $0.75 AVR chip they currently use but we're talking high end keyboards here.
So where is that keyboard?
Just to be crisp here, an STM32F429 can have 135 digital I/Os in the 208 quad flat pack. It also has a megabyte of flash and 192K of RAM. It also has a USB Phy built right in so you can just wire it up to a USB connector. Its $8 in 1K quantities in that package. So parts : chip, PC board, 120 or so switches and plastic case and key caps. Sure its more expensive than the $0.75 AVR chip they currently use but we're talking high end keyboards here.