The entire topic is complex, and like I said the main point wasn't about template vs. SPA, although I felt like something had to be said about it, as it's obviously related and something of an elephant in the room.
I don't think there is One True Way™, but I also feel that many apps are actually a lot less complex than people seem to think. For example the main competitor for the app I'm working on now (unpublished MVP that's still WIP) is a SPA, and I feel like my simple template-driven app has a much better UX. You just don't need all the complexity, there is so little benefit you might as well not bother. I think this describes many apps.
Would HN be better as an SPA? I don't think so, and I suspect that a "SPA HN" would be harder to develop and get right.
Also - as someone who disagrees with you I don't see any compelling points in things like:
> "So when the author says that classic HTML with sprinkled js on top is "easier to develop", I smirk. If it were, developers would not be flocking en masse towards SPAs and the like. Those are gaining traction because they are easier to develop and easier to maintain. Monumentally so."
You're on HN - there's a huge chunk of us who are attempting to KISS web development. You're not wrong that React and Typescript are wonderful tools - but they're absolutely not the only way to develop things.
Also you may want to address people's worries about SPA development if you want to convince people it's not as bad as they're saying. (like performance - which is a huge reason I keep my light-weight vanilla-style apps the way they are)
Performance is a concern, and that's one of the main reasons why serverside rendering is being adopted as a technique. So when OP berates the existance of SSR, I have to wonder if they understand the larger picture. If it's rude for me to point this out, I apologize for being rude; my point still stands, though.
I don't think the SPA approach is the end-all-be-all but I'm definitely happy to have adopted it for my current project (a mid-size web app mixing classic list views and a few more complex bits and pieces here and there). Had I done it with jQuery, I'd still be building it; and had I done it in my classic hybrid approach, I would not have as many options as I currently do when building new pages/views.
I'm starting to think I need to clarify that paragraph :/