Have they? Genuinely asking. The recent code samples I did see on SO don’t yet include them and the one big Python project (Django) that I use hasn’t started making use of then just yet, or at least not to my knowledge.
IME they are increasingly used by application developers but a lot of libraries and even Python's own documentation have not really embraced them yet. That makes using them a lot harder - and sometimes less useful - than in comparable languages like TypeScript. Every client we've worked with recently who uses Python was at least trying to use type annotations but not necessarily with the same level of commitment or expected ROI.
