Isn't geothermal theoretically available everywhere?
I believe that the issue is that the Earth's crust isn't uniformly thick, and that there are places where one could drill for miles without reaching magma/suitable heat sources, and other places (Costa Rica and Iceland come to mind) where the suitable heat sources are essentially on the surface.
Or, looking at it another way - oil drilling happens all over the globe and "hitting magma" isn't really a risk they're concerned about because it's so deep, that even the industry concerned with drilling too greedily and too deep doesn't intersect with it.
The tech is still at pilot stage, but with no fundamental problems to solve. The important question is whether it will be able to compete commercially with solar and wind, which costs are still in free-fall.