Non-macOS user here on a random laptop: when I type Fn+<some key> and that key doesn't have a special function that can be invoked using the Fn key, the result

Non-macOS user here on a random laptop: when I type Fn+<some key> and that key doesn't have a special function that can be invoked using the Fn key, the result is the same as not holding the Fn key. If the behaviour of the Fn key were inversed (i.e. keys with special functions perform that function unless the Fn key is held down), I would still expect regular keys to work normally no matter where on the keyboard they are. The F# keys aren't special.