The natural world is in danger, so there's no better way to draw attention to this crisis than drawing the world's eyes to a great historical wonder. The orange coloring will wash off, but the climate won't be as easily healed. Serious action must be taken to reduce fossil fuel consumption, so severe measures must be taken to draw attention to the climate emergency.
These acts don't gain support for Just Stop Oil's cause — they create anxiety and annoyance. Some people affected might sympathize with the organization's climate concerns, but they'll likely be alienated by seeing Stonehenge or any natural wonder or precious works of art damaged. There are better ways to spur more action on the climate crisis.
Dark climate fantasies are getting more cultish and dangerous. The narratives of eco-extremist movements are becoming much graver, more apocalyptic, and have dangerously lost connections to reality. This trend must be watched closely.