I used to think the same about server-side rendering until I more closely looked at React SSR.
I think it makes a lot of sense and allows for faster initial rendering of the page while automatically setting up the JS and interactivity in the background.
React has always supported server-side rendering and there have been many tools over the years to "rehydrate" data from the server to the client for when the client-side React application "takes over".
Couldn't you just static render the parts that you're using SSR for?
I am not trying to be dismissive, but a common strict requirement is static hosting from a CDN, embedded environments, etc.