Current AI is at least a few orders of magnitude less efficient than it could be (as evident from biological spiking networks, e.g. human brain). At some point the labs put too much work and money into transformers and nearly abandoned fundamental research, in both ML and hardware. There are tons of low hanging fruits in efficiency but you'll have to redo everything from scratch so nobody bothers. Which is also pretty convenient and lets people like Dario Amodei speak about "natural concentrations of power".