It's a good intuition. Indeed you can see it as ReaderTaskEither (albeit on steroids). The fp-ts author is also an effect maintainer and recommends effect for

It's a good intuition. Indeed you can see it as ReaderTaskEither (albeit on steroids). The fp-ts author is also an effect maintainer and recommends effect for new projects. fp-ts is not dead, but it's core goals (providing Haskell/PureScript-like types and type classes) have been mostly achieved. Effect is an ecosystem with different goals from fp-ts.