Here's an interesting article:
https://www.npca.org/articles/1195-national-park-visitation-generated-32-billion-for-national-economy-in-2015We've volunteered in national parks and didn't see the rangers goofing off or absent.
We volunteered not for the free campsite but because we wanted to help out in the parks we love. We never put a dollar figure on our hours put in. We did it because we wanted to do it.
You don't have to volunteer in these parks. If you don't there are many others who will.
The parks help the local communities by lodging, restaurants, and giving people jobs.
People come to these parks for a reason. Think about what would have happened if they weren't protected.
Oregon has protected practically the whole coast with their state parks. If not, the coast would be filled with condos for the rich and common folk wouldn't be able to enjoy them like they do.
We have no criticism of the national parks. They do a fantastic job with what little they receive.