I recently had to replace the majority of windows in my home in the US. I was appalled at the options and gimmicks and downright shady sales tactics. I ended up having custom windows made to get what I wanted. Maybe it's a "grass is greener" thing, but I'm envious of how it seems people are just more honest in the Nordics.

Meanwhile quadruple glazed window enjoyers have their laugh at your expense.

Like they said, that's the minimum. Usually those are efficient enough so you can have a single window unit with a pane in the middle, but quadruples are common too.

Unfortunately, having more panes of glass does not automatically mean you get more energy efficiency.

The triples with very good insulation and coatings (eg. heat rejection) can be better than old quadruples. My parents have quadruple windows from the 80's, and energy efficiency is much better in a modern triple single unit than with the two doubles they have.

I've gone through the same in Australia and the "modern double glazing" in practice meant importing windows from Poland. Literally shipping around the world was the most reasonable option a few years ago (hopefully it's better today) while really crappy houses burning energy to heat/cool every room are still being built as a default idea.

In South Africa, double glazed windows are usually imported too (the parts) but they are assembled here so that they can get your measurements exactly right.

This completely misses the point - we are talking about easy wins. There is zero point putting triple glazed windows in a 200 year old house that isn’t otherwise insulated