I would argue that home owners insurance is a commercial application of volcanos. No, it doesn’t harness them, but if you live somewhere that could potentially be affected by an eruption, your insurance company is paying attention to the science in figuring out how to cover that risk.
To to put it another way: We can derive value from knowledge about a thing, even if we can't feasibly direct its behavior.
Ex: Tracking Earth's seasons, inventing calendars, and adjusting agricultural practices. Or ancestors didn't control the tilt of the planet, but...
It's my understanding that insurers typically exclude volcano related damages from their policies, particularly lava and mudflows and earthquakes, so they can treat those risks as if they don't really exist.
Every source I can find says that most homeowners insurance will cover direct damage from volcanic eruptions, including fires, with some exclusions like mudflows.