Your jQuery example illustrates something different.

But this isn't the problem of your example. Let's talk about state, assume doSomething() queries a REST API endpoint to fetch a user profile consisting a name, a Base64 encoded JPG logo and a URL to an external logo. How to you want to share the state aka the result between at least those two components? What if some more elements need to know about the user profiles content? You can either reference each element to each other and share the data by teaching your Name element how to feed the Logo element and that this Logo thingy needs a URL or a JPG to function well. Your Name element is now the parent element which knows about itself, and it's children the Logo-element. In fact, we have no Logo element anymore; the Name element assimilated it, silently.

You need to have the data sharing logic outside of each of your elements. But because it's jQuery you will end up having a function which queries the DOM for each element to put a text into the Name thingy and an image or URL into the Logo thingy. The exact implementation detail how to feed your element is now not part of the element anymore.

In contrast, React has a defined communication interface: props, state, and events. Redux as a state manager cares for state and manages them in a single tree; very similar to the component tree in the DOM of your app. Sharing state with data as the payload is easy now. Actions cause Reducers to create a new state. This state is shared between all components which registered to a particular action type. Redux doesn't need to know any detail about any component, and yet still it shares changed states correctly. Instead, each component cares to extract it​s data out of the state payload. The same way each component gets its data from props.

Does it make any sense to you?

This might be a good start: Getting Started With Redux