The differences between simple cycle and combined cycle turbines - https://en.wikipedia.org/wiki/Gas-fired_power_plant#Gas_turb...

I'm not in this space, but I seem to recall that manufacturing capacity is badly constrained for these power plants. With the stupid money being thrown at AI now - having 2X the efficiency may not matter much, if the extra complexity means they can't ship at least 0.5X the units. There's also the much slower dispatch time issue, and folks building AI DC's may just not want the added complexity.

(And yes, a startup that just came out of stealth with $8M may be a long way from shipping anything more than a few little demo units.)