The 2 year later bugfix is often easier I agree. But for me by far the biggest difference is speed and effectiveness in writing new code. I'm not just much faster, but also much better with typed code probably because it fits the way my brain works better.

> Is that not how everyone writes static typed code?

For me the process is a bit opposite. I tend to write the interfaces first, usually until the entire routine of whatever I am writing is complete. So e.g. only the types accepted and returned by functions, but not the actual function itself. Then I go back and add the code itself usually at the very end.