There are definitely many companies willing to throw millions a year at AI, and are currently doing it, but as it stands today, it doesnt sound like they're getting the return on investment they expected.
It can change if the models actually got better, but how much of it is inherint to how LLMs are made, and/or how much more can they be improved before this all falls apart
It cant go on forever as is today.
In theory costs could come down with each new hardware generation if the we dont keep pushing models the to max extent of what the hardware can do while pushing size.
E.g Claude Opus today, only trained in a similar size and manner as today, will be cheaper to run on whatever the next GPU that comes out with higher speeds and processing capabilities, unless of course NVidia raises the cost substantially. Given the current situation I think nvidia might do that which would hamper this lowering of costs, but it should possible, if not slower.
E.g 10 years from now it will be cheaper to run a opus similar model. But 10 years from now everyone will want the mythos of today, then. That wont be cheaper.