the national parks are almost fully funded by the people that visit them.
I do not use any of the Local Parks, I do not pay Pokemon Go, I do not have a use for either
People that use the parks should pay for them, then if there is an increase in activity from something like Pokemon Go that means Revenue also increases to pay for the increased costs to maintain the asset.
I am fine with that, it is not ethical to take money from people by force to pay for things like this, if their was value in the community for a park then the community would find a way to voluntarily pay for it, if there are not enough voluntary support in the community to fund the park then the park should not exist
Even if that were true, National parks are big, which means the additional space taken up by toll collection infrastructure at parking areas (and the staff to man them) aren't a big deal, and they present lots of needs for people to stop and buy things which creates concession opportunities.
This is significantly less true of most (but not all) local parks.
But, anyway, even National Parks funding comes mostly from appropriated funds; fees (both directly from visitors and commercial services) are on the order of a couple hundred million of the single-digit billion dollar annual parks spendibf. And even that amount actually spent doesn't meet upkeep needs; the National Parks have deferred maintenance costs on the order of four times the annual budget.
Source on this? I feel like if this was already the case then the issue of cutting national park funding wouldn't be such a big deal, and yet it is.