>The point generalises beyond semicolons; everything you leave to context is something other people have to load up the context for in order to understand.

This is not true, because an editor can add any on-screen hints that are needed to help a human understand the code. For example, in my editor, Python code gets vertical lines that indicate where the different indentation levels are, so I can easily see when two lines of code far apart on the screen are at the same indentation level, or how many indentation levels lower the next line is after a long, highly-indented block. Python could add an end-of-block marker like Ruby does to make things like this easier to see, or it could try to encode the vertical lines into the language somehow, but I'd derive no benefit because the editor already gives me the visual clues I need.

I haven’t used type hints in Python, but can what you’re describing lead to situations where the code cannot run and the interpreter gives you a suggestion on how to fix it?

Type hints have no runtime impact, so they can't make stuff not work.

Type linters like mypy can check your code & report something like "this function call requires str, you're providing str | None" though.