First of all, React is a library and Angular is a framework. Developers these days have a complicated relationship with Angular. It is not wrong to say that they are getting stuck in the middle of a simple app for weeks. Even for simple features, you need to struggle a lot so, it's difficult to say that is it worth using Angular.
Although you have thoroughly grasped the basic fundamentals which should be enough to code small features. Unfortunately, it didn't work out. That's why finally developers gave up Angular and adopted React as an alternative. The react learning curve is smaller and blending libraries is also easier.
React is an Innovative Space
React have building blocks that provide flexibility to pick a suitable block to fix your problem. It allows exchanging building blocks for experimentation and adoption, which makes it innovative.
State management is done through MobX and Redux and enables exchangeability with Preact and Inferno.
While this approach is not possible with Angular, as it delivers its own solutions.
On another side, Angular doesn't allow us to mix view and logic.
There is an ES6 class component method SetState() which can update the internal components state.
There are concepts like state and props regarding which you can explore in the official documentation of React. One can easily use the view library to solve problems.
The functional stateless components are functions without a boilerplate. It means you use them while accessing lifecycle methods or component state.
Thus it makes the components lightweight, small, and reusable.