Assuming you add video, 99% of the web is just text,images,links,forms, and video. None of these things even require Javascript.
Or is your opinion that it should only be possible to do those things in native, purpose-built apps? Because in that case, how do you justify using an operating system? Perhaps we should exclusively use purpose-built assembly code that you flash to some writable media every time you want to run a particular program!
Also, a SPA is not the only option with Javascript.
1) Load the page.
2) The page is now fully loaded and ready for reading without any need for further network requests.
For even more offline use, try printing it! HN threads work superbly when printed, again unlike most modern sites.
Or you could reimplement newsgroups (but with less interoperability) as an SPA, which in theory would work great (once you work out the kinks) but in practice would suffer from all kinds of little issues in the from-scratch reimplementation of everything. For example, printing would probably forever be a wishlist item in the backlog.
A lot of people think that moving to an SPA would mean killing both those aspects. But the truth is, you CAN have an SPA that is both lightweight and fast - the developer just needs to know what they're doing.
Not sure you could ever call them an anti-pattern.