React.js is really efficient :
React.js is really efficient, as it creates its own virtual DOM by calculating the necessary changes in DM beforehand and then it updates the DOM tree, avoiding the expensive Dom operations.
Awesome for the Search Engine Optimization:
It is amazingly awesome for the Search Engine Optimization because it has inbuilt SEO features. It stands out from the rest of the competitors, as it can run on the server.
challenges in single component:
You have a solution if you find any challenges in single component. Using React, you can break it down into smaller ones and solve it there. You can also reuse it somewhere else later if needed.
Component driven development,
Component driven development, smaller pieces and work with less responsibility. Breakdown your website to ease the reusability.
React js need
The last but certainly not the least, the teams behind Facebook, Instagram, Yahoo! and Sony are maintaining the project, what else do you need?