I think this is the key element. Either they can't measure the value, or it's far far lower than anyone wants to believe, or both.
I think the problem is less that it makes some coding tasks XX% faster, but that the end to end of a SWEs roles tasks is only improved by some much smaller Y%.
If a CTO sets $10k/year spend limits on $500k SWEs.. they must not believe any of the hype.