Browsers are pretty good at loading pages
Page load speed is not the only reason why client-side rendering is important. When traditional server-side rendered pages need to update state on the page they have two choices: Use DOM manipulation or reload the entire page from the back-end just to update one small piece of the page. The more state that needs updating, the more complex it becomes to manage rendering on both the server and the client. Code redundancies creep in as html templates are duplicated on both sides.In my experience, as soon as a website has any app-like qualities at all, a tool like react just makes sense. It's a great tool that solves a very real problem. I always use universal rendering so that you get the best of both worlds and the page still renders fine for the no-js folks out there (respect).