The point from from old England’s perspective is that keeping the grass at 2 cm requires a whole bunch of resources and people, so only the rich could afford it. Even today, any neighborhood with weeds growing instead of a 2cm lawn is instantly classified as lower class. There often is no practical use or sometimes use for games or walking is when forbidden because it’s a status symbol only.
It’s like asking what’s the point of owning a Bugatti Chiron that can go 400 kph when you’re stuck in the same traffic jam anyway.