Viva, the helicopter that spotted the first monolith in Utah was taking big horn sheep counts. They weren't out there looking for illegal art installations.
I think most of these are copycats of the original Utah one. In my opinion it's just pent up energy from the frustrations caused by covid lock downs. People need to move around, be productive, accomplish something. There are still a lot of people around the world with a lot of extra time on their hands.