Every time I talk to developers who use frontend frameworks, I challenge them and say: Let's sit down and build the same application. You build it with React or whatever, I build it with plain JS. Let's see which one is leaner and more logical.
Every time the answer is the same: The benefit of a frontend framework will not become visible in a small app. Only in a big app.
Then I ask: Ok, where is the cut off? What is the smallest app, where React will shine? And I never get an answer.
When I see React examples like this calculator ...
https://github.com/ahfarmer/calculator
... which use 70 files (without dependencies!) to build something one could do in a single HTML file, I am afraid that those "big" apps the React proponents talk about will be very big when implemented with React.