Personally, I have a bad working memory and struggle to remember the structure of data. I constantly have to jump around and try to find the name of things / recall their hierarchy

With static typing I can just highlight a type / jump to the definition or get intellisense. I also find it useful when I have specific names for data types because I can reason about things / communicate them easier

To me taking the time to specify types or wrangle the type checker is worth the reduced mental burden of having to remember the shape of things, and refactor data structures confidently

Same problem with all dynamically-typed languages, really. It's too easy to write the wrong thing and not find out about it until you've written umpteen unit tests. This can happen due to typos, refactoring, or whatever else. Only JavaScript is worse because it's weakly typed too, so it performs implicit coercions in an effort to make your code always do something (meaning your unit tests have to be very good to really ensure your functions do what you think they do).

A static type system ensures that, at the very least, all the types line up at compile-time. You find type errors much faster than with a dynamically typed language, and this can guide a much less exhausting development cycle.