As someone who's worked in the industry for a long time in the past. Driving ranges are for practice. Courses are exceptionally harder, the actual game. And I do agree they waste resources. But in the end, minus the waste of water, at least they're being kept as green spaces.
To be clear I used to work for the government in this regard. The spaces would've been cleared for commercial use otherwise.
While I do find golf pretty boring. I'd like our established courses to remain.