React is not perfect, it's bloated, but the reason it took off is that it brought something new to the table as a general and programmatic way to construct UIs. Being a child of Facebook helped it achieve dominance but considering that before React we had angular (shudder) and jquery, React's success was well earned.
React will be replaced when something actually better comes along. The current contenders seem to want to return us to the technology of the past, it didn't work then and it doesn't work now.