Mixing types in an array/list is not remotely stupid. How exactly would you suggest expressing the lack of a value in a series of numbers without None/null? There's your mixed types.
Don't let weird dogma get in the way of practicality.
That is merely a detail of how the typing module has decided to set up convenient aliases. Treated by the language (and likely compilers) as different types.
Don't let weird dogma get in the way of practicality.