Without Serverside Rendering in React - The Basics | Contabo Blog

If server-side rendering (SSR) is not used in a React application, the application may suffer from slower initial load times, as the entire page needs to be rendered in the client's browser. This is because CSR renders content dynamically using JavaScript after the initial HTML page has loaded, which can result in delayed content visibility for users.

Additionally, SSR improves SEO performance as search engine crawlers can effectively index web content without executing client-side scripts. In contrast, CSR content may take longer to become visible to search engine crawlers, potentially impacting a website's search engine rankings.

Not using SSR could also lead to inconsistent user experiences across different browsers, as the rendering is handled by each browser individually. This may result in variations in how the same web page is displayed on different devices or browsers.

In summary, while CSR has its own advantages for interactive and dynamic web applications, SSR provides benefits in terms of initial load time, SEO, and consistent user experiences when rendered content is a priority.