Optical Key Switch
Optical key switch became popular around 2016, due to the Bloody B840 Optical Switch Keyboard using the “Bloody LK Optic 2 switch”.
Optical switch is great because it does not need metal contact. Meaning, no wear, last longer, and easier to be water resistant.
Optical Switch Manufactures
Optical Key Switch keyboards
There are a lot. Here's a few example.