Actually, you do see a lot of questions and problems with the single state atom. In fact, I'd argue it's inherently a side step towards a future that has the best of both worlds: encapsulated state within components, but backed by some global state store invisibly.
This is exactly what Relay is by the way. You component asks for state, and gets it from a server. The fact that it comes through props is actually just a downgrade because it means you must now treat it as some special thing, and not variables.
In the ideal world, we can write simple components that fetch state from wherever (remote, local, global). They store that state into themselves, and it "just works". They can write back that state just like how they write variables. And all of this "local" state would really be backed into a global state store invisibly.
Local state - Pros: easy to reason about, easy to use. Cons: trapped in one place, inflexible.
Global state - Pros: can be backed in various ways, easier to share. Cons: Hard to use, harder to reason about.
Local state backed to global store - Has all the pros and none of the cons. Unfortunately doesn't exist yet today.
This is exactly what Relay is by the way. You component asks for state, and gets it from a server. The fact that it comes through props is actually just a downgrade because it means you must now treat it as some special thing, and not variables.
In the ideal world, we can write simple components that fetch state from wherever (remote, local, global). They store that state into themselves, and it "just works". They can write back that state just like how they write variables. And all of this "local" state would really be backed into a global state store invisibly.
Local state - Pros: easy to reason about, easy to use. Cons: trapped in one place, inflexible.
Global state - Pros: can be backed in various ways, easier to share. Cons: Hard to use, harder to reason about.
Local state backed to global store - Has all the pros and none of the cons. Unfortunately doesn't exist yet today.