Honestly, after using mobx, it's almost impossible to understand why Redux is popular. MobX is more concise, more performant, has a crazy amount of built-in optimizations, and lets you forget about tracing your crazy graph of relationships just to update some view.
Of course, mobx had "bad" (read: used decorators) syntax for a while, and only with MobX 6 did they clean it up, but boy oh boy is it clean now