If curing cancer or solving climate change is your definition of usefulness, almost anything humans do is useless, probably including your own profession. Though I don't want to speculate. Speculation is precisely why NFTs are stupid. Claude, on the other hand, if used effectively, can speed up people's work and increase productivity.
Is the high expense coming from cache misses? If their workload does need to wait for a long time before it can continue, I wonder would starting new sessions and having to re-read the contexts and results anyway be any cheaper.