Maps, GPS apps, Google Docs, editors like Atom or VS Code, games, calculators, data graphing (particularly if the data is, updated in realtime via push),, chat clients..

Anything that actually warrants being an application.

I only really object to "CSR only" when it's utterly unwarranted like a bunch of content paragraphs and headings, simple tabular data, simple forms, purchasing, etc, etm. Basically CSR doesn't belong anyplace there's actual important STATIC information being shown, that could be conveyed in a fraction the code and overhead, or where simple forms for essential services are required.

You DO NOT DO IT on banking, government, medical, public utility, or retail sites. Same as crapping out layouts in PX, using fixed width layouts, hard to read fonts or colours, and ignoring basic semantics.

Again though, nothing wrong with using JS to enhance an already working page!

Seriously though, how many times have you said -- or heard people say -- "No I don't want to install your ****ing app!" typically for something that has anything more than a static website?

I've heard it from others a lot. In public!