Even having type hints on basic functions like def foo(bar: str) in a throwaway-script helps because it gives me reliable autocompletion on bar. I might be getting old or toggle between so many different languages nowadays that even basic stuff i don't want to remember, like whether it is bar.lower(), bar.lowerCase(), bar.toLower(), bar.toLocaleLowerCase().

Defining a data structure up front doesn't require a lot of boilerplate as Java incorrectly have taught all of us. Writing a statically typed typing.NamedTuple or @dataclass is literally a one-liner.