Sagas are a great power tool, but most Redux apps don't need them. That's why we opted to include thunks out of the box as part of our official Redux Toolkit package:

https://blog.isquaredsoftware.com/2020/02/blogged-answers-wh...

(You can still customize the middleware when using RTK to set up your store, same as always, so if you want to use sagas you still can.)

That said, there's a lot of things thunks _can't_ do, and for those use cases it makes sense to use sagas or observables.