GNSS is also an 'umbrella' term for many different types of satellite-based navigation solution, GPS was the American set-up.
As for the rest - agreed, shambolic situation and utter mess that helps no single person understand with a logic applied. Typically aviation. Makes you want to vomit. Lets not start on RAW TAF's, METAR's and NOTAM - Like we still need such gibberish in required information.