It's also not that different from what people have been using Task Lists for today: https://docs.github.com/en/get-started/writing-on-github/wor...

I think that's maybe my biggest question is what the interop looks like between Task Lists and Sub-Issues. Is there a "one-click upgrade" yet? What if I want to copy a list of Sub-Issues as Markdown Task List to copy into a Discussion or a Wiki somewhere?