If I'm one of Reacts competitors I'm ecstatic that they're abandoning the web. It reminds me of when Angular wastes energy on angular.dart because of a Google mandate. Didn't help them much.
angular_devs ∩ dart_devs ~= 0 (relative to angular_devs) react_devs ∩ mobile_devs ~= react_devs
Almost everyone who uses react also has to do mobile development, and would like a simpler way to do it. This solves a real and widespread need.