Too Long; Didn't Read
React 18 is a major improvement to React’s rendering mechanisms. It focused on improved performance of user interfaces for a much better experience for the user on the website. The newly added features are completely user-centric, to make sure users don’t wait too long before interacting with the website, which translates to significantly less bounce rate on the site, more lead conversion, and increased revenue for businesses. The new root API is the main feature that introduces the concurrent rendering mechanism, which is the coolest thing about the React 18 upgrade if you ask me.