Focus on the problem that is being solved, not the mechanism. Consider this classic trick:

    handle = (exists(file) and open(file))

That uses the short-circuiting behaviour of && to only open a file if it exists. Not great practice to write it in that way IMO but whatever. You can't implement it as a function:

    handle = and(exists(file), open(file))

    def and(exists, file):
       ... No viable implementation in Python afaik ...

That doesn't work because functions arguments don't/can't implement short circuiting - both arguments are evaluated before our function is called (although we could make it work in this case by passing the file name in - the point is that the function signature has to change).

Macros however can implement something that has short circuiting behaviour. It is a mechanism for implementing new syntax - more powerful than functions but as a trade off more error prone. Quasiquoting and whatever falls out of that as implementation details once you've got all that as context.