Yes, they are probably most useful to me for the IDE completions and docs as well. Raymond Hettinger gave at least one talk [1] where he discussed how there are tradeoffs: reasons why you might use them and reasons why you might not. At the end of the day you can pass whatever you want to a function and the only reason to use types if they make your code better—but there are other tools that might be more worth your time in some situations.

[1]: https://www.youtube.com/watch?v=ARKbfWk4Xyw