Why are they building so many data centers then? That is all cost that has to be earned back. And using them as agents creates much higher costs per interactions than just chatting. We also don't know if the current prices are in any way economical, or how they are related to actual development and interference costs.
Do you think people should have not invested in data centers because of moores law that also applies for cpus? Same mechanics applies there - turns out that when things get efficient, demand increases and more possibilities are unlocked.
When Moore's Law was still effective, did you ask why people produced chips?