dA few years ago I had enough not to visualise all my tasks from different apps and was pleased to find services like https://tacoapp.com to do just that.
Now Microsoft is also addressing this by integrating a central tasks dashboard inside Teams.
I am looking forward to seeing this enabled on our tenant, test it and review it.
Introducing Tasks in Microsoft Teams :
Update 7th Jan 2020: still no release date to be found.