That depends on the energy source, and how much is available. If for example we convert to 100% wind/solar/battery, we'll end up with a large oversupply of zero-carbon electricity in the summer.
It seems reasonable to assume that many places where there is easily accessible volcanic rock are also places where geothermal is possible, but the connection between rocks like basalt and volcanoes can be more temporally distant that you may be thinking.
If I go to a beach in the US Pacific North West, I can pick up basalt rocks/boulders/pebbles, but they last were in contact with an active volcano millions of years ago (approx 12mya is the usual number given locally, if memory serves)
The argument is basically that we will need extra energy to go towards carbon capture one way or the other. Energy in, carbon reduced. This may or may not be a feasible way to do that.
