The lack of the "nursery" concept for asyncio really sucks. Originally I heard it was coming in 3.8. Right now asyncio has this horrible flaw where it's super easy to have errors within tasks pass silently. It's a pretty large foot gun.
Like https://github.com/Tygs/ayo
It's not as good as having it in the stdlib, because people can still call ensure_future and not await it, but it's a huge improvement and completly compatible with any asyncio code.