As Eli Dourado wrote, “there is 23,800 times as much geothermal energy in Earth’s crust as there is chemical energy in fossil fuels everywhere on the planet.”

And every hour, The sun blasts us with enough energy to cover for a whole year - without drilling millions of holes, cause who knows how much problems.

The thing is: geothermal is very spread out. About 10 MW per km² is a number for an actual geothermal site (not a random location). Another way to lock at it:

The Earth’s internal thermal energy flows to the surface by conduction at a rate of 44.2 terawatts (TW),[21] and is replenished by radioactive decay of minerals at a rate of 30 TW.[22] These power rates are more than double humanity’s current energy consumption from all primary sources, but most of this energy flux is not recoverable.

So while there is a lot of energy stored in the ground, we can not simply remove that. Just covering our energy demand would mean that we remove more heat than what is replenished. I doubt that messing with earths heat flow on a substantial scale is going to be a good thing.