I think that approach is fine if you have an application that's light on interactivity (like school curriculum or tutorial, in his case).

And I agree 100% on the service workers (Seriously, I'm right there with him - they're magic). I would also recommend leaning more heavily on persistent storage (localstorage/indexdb) but I'm also trying to handle offline only cases.

I think some of the advice falls down when you're genuinely trying to create an interactive experience. I probably won't expound much farther, since I really try to keep business out of HN, but... I write applications that have been used for following treatment programs in education environments - think speech therapy or ABA for autistic students, where the user is inputing data frequently - as often as once a second - and the UI is updating in response to calculations done client side, that influence the instructors program and plan in real time.

It's a lot of screens, often customized locally on the application, and removing JS (or even just writing pure js) hurts a lot. That's... hard to do with minimal js. Really, really hard.