The government often claims exclusive authority and responsibility over the land but never acts on the responsibility they've asserted except to prevent anyone else from doing so. You can be required to pay a significant fee and file reams of paperwork to fix things for free that the government is expressly obligated to fix but never does.

It is common in parts of the US for government land to be illegally maintained by locals at their own expense because the government fails to do so. The impacted people aren't left with many other choices. There is little recourse when the government claims sole authority but also neglects its responsibilities under that authority.

This has been an issue in land management for as long as I've been alive. It sort of works to the extent the government is oddly incurious about someone else illegally doing their job for them. But every so often a bureaucrat with idle hands will decide to make an example of someone for illegal maintenance without addressing the underlying problem.