A lot of them are. Those that weren’t still hurt the environment in both construction and maintenance. The runoff of fertilizers can cause algal blooms, and the runoff of pesticides and weed killers can cause CATASTROPHIC damage to the local ecosystem. It would be more eco friendly to play tether ball, cornhole, or have a BBQ with the boys. Hurting the environment isn’t necessary for a good time.
The action to inaction ratio might be the lowest in all of “sports” (we’re using that term broadly here). You hit the ball and then spend a shitload of time chasing after it, which makes it basically fetch for humans. Compare that to a sport like tennis or basketball where there’s something for you to do almost 100% of the time. Imagine if in basketball every time one team took a shot everyone just stood around for the next five minutes. That’s how shitty golf is.