Allow to sort subtasks by complete/incomplete

Not at all, @Phil_Newby - there are multiple examples of changes that people started asking for years ago and after a number of years, were implemented.

You might also want to read this post for some additional context: 🦄 If Wishes Were Unicorns: Why Asana Might Not Have Implemented that Feature Request (and other thoughts about Asana feature development and product strategy)