I once curiously asked this to Richard Campbell after a couple great Geek Out podcasts on geothermal & super volcanoes. I was told the difficulty in volcanoes

I once curiously asked this to Richard Campbell after a couple great Geek Out podcasts on geothermal & super volcanoes. I was told the difficulty in volcanoes vs other popular geothermal sources is that volcanoes are an "unstable magma chamber" which makes it very difficult, expensive & risky. Of course if this could be perfected, it could be a huge source of energy not just on Earth but places like Mars as well.