At the very least, latex could be upgraded to accept unicode characters for certain things like the greek alphabet.

For instance, while writing, the user inputs \alpha and the editor automatically converts it into the greek symbol right there in the source file. Later, when compiling latex transparently recognizes the greek symbol for what it is.

I like the way Julia does it - full unicode suport in the language, and easy input in the repl and notebooks with a simple backslash escape sequence. \pi -> [tab] -> π

Sometimes I fire up a Julia repl purely as a unicode-getter.