Are gallium based chips completely non-viable or something? I thought they were the next big thing in chip materials that would let us get past the Moore's law restrictions in silicon?
If you're looking for exotic materials to bail us out, it might be a little less hopeless to look to diamond or to high-temperature semiconductors.
Silicon has never really been the most ideal material for transistors, but it has always been so cheap in comparison to be the most cost effective.
The joke about GaAs is that it will always be the material of tomorrow. (They've been using it in lab settings for decades)