As I understand it, only components that read from context render when state changes. If you want/need more granular control, you have Memo at your fingertips.
Further, the entire point of global state is you only put the stuff in there that might actually require child components get re rendered. If you're shoving everything into global state or using context when you don't need it you're doing a lot of things wrong and it's likely you'd abuse redux as well.
Further, the entire point of global state is you only put the stuff in there that might actually require child components get re rendered. If you're shoving everything into global state or using context when you don't need it you're doing a lot of things wrong and it's likely you'd abuse redux as well.