Some other people in this thread suggested having a keyboard with little e-ink displays on the keycaps. Then the character map could be completely user-defined. Then you could just have a big bank of keys off to the side to select your desired set of characters, i.e. greek, math, emoji etc. You can already sort of do this in software, but you have to manually remember the location of every character in each extra mapping. But with displays on the keycaps, you could have as many different mappings as you want. And that's how you would be able to type in a sane world