Hi Mazen. My points about using Next.js/Nuxt.js is if you're already using modern SPA frameworks like React and Vue, then Next.js/Nuxt.js allow you to continue using those frameworks but with SSR features baked in. You have to use Node.js as a backend technology, but all it's doing is rendering your front end application.
Having said that, you really just have to evaluate your use cases. If you're comfortable using a traditional monolithic framework like Ruby on Rails, Laravel, or Django, by all means go ahead. If you're also just building apps behind a login screen, like a mail client, then you'd be better off building a SPA without any SSR.
As far as drawbacks go, I would say SSR does introduce complexity such as having to run a Node.js server. Performance is pretty good when using a framework like Next.js, but that doesn't mean that you can't slow things down by fetching too much data server side or just having a slow server.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.