Spot on, IMHO. A tiny fraction of the energy going in succeeds in storing carbon, and that energy could be used at 100% efficiency to displace carbon-based energy generation. So yeah, absent near-gratis and otherwise useless energy, it’s a waste of effort.
The following article, however, is downright hopeful. TIL lots of useful crops are shade tolerant, especially when that shade is in parts of the world where soil is getting slowly smelted into glass by climate change.
Edit: More from the Fraunhofer Institute:
