Consider supporting React 17

[SimenB]

👋

React compiler supports targeting React 17, so we have begun introducing it into our legacy code base. This code base is stuck on React 17 since it uses reflux. We have started to migrate to MobX instead, but since MobX is not compatible with the React compiler, we have instead decided to attempt to migrate to react-query. However, v5 only supports React 18+, so we have to use v4.

Would it be possible to extend support in v5 down to React 17, to match what React Compiler can target?

https://react.dev/learn/react-compiler#using-react-compiler-with-react-17-or-18

[TkDodo]

Sadly no because we use useSyncExternalStore which only exists in 18, and the shim for v17 was very troublesome for us in terms of bundling