Building an SPA for every single project is like using a semi-trailer to commute everywhere you go. Sure, it will always get you where you need and sometimes turns have to be taken pretty wide, but what's the downside?

Well, if you're destination is just 2 blocks down the road then why not walk? If you just need a simple page and the content doesn't need to be updated often, why not some flat HTML/CSS/JS?

Many times SPA frameworks are used because it's flashy and more exciting than writing basic html and css, but more often than not that's all you need.

I didn't consider small static sites. I agree with that and have done some landing pages that way that stand in front of SPAs. I guess I was commenting on OP wanting to use Rails or Spring MVC for views instead of only using them for APIs.

I'm not sure what the term for it is, monolith maybe.

I believe the term would be "Server-rendered MVC framework". I think the argument for server-rendering is simply productivity. You can probably get stuff done about twice as fast if the use case fits the paradigm.

It's nice when I don't have to enable JavaScript just to use a website. My battery appreciates it at the very least. Forcing me to run arbitrary Turing-complete code from the Internet just to, say, read an article or buy something online is not okay, especially when that code exists solely to either 1) spy on me or 2) reimplement half of my browser.