I think you're missing the point
Think of these technologies as an all hands on deck approach, rather than as a conspiracy to keep burning fossil fuels. Of course we need to convert to renewables, and we are at least at the moment. It might not be a bad thing to also reduce the current amount of CO2 in the atmosphere if possible, and create usable and valuable byproducts in the process.
"...what the hell would we do with 37 billion tons of graphene?"
Uses for graphene.