The article mentions this, and says these new transistors actually take advantage of quantum tunnelling at those small scales to switch the transistors on and off. Usually that’s accomplished by charging up a conductive channel in a traditional MOSFET like a capacitor.
The disadvantage seems to be that these transistors can only control very tiny currents. They currently lack enough ass to control much else.
That’s basically how IGBTs in power electronics work, in stuff like trains and electric cars. It’s a sensitive, easily activated voltage-driven MOSFET driving a larger BJT transistor in a chain.
Also how Darlington pairs work. So, yeah, maybe they could do all the computation at that level and then cascade the output through larger transistors to talk to the outside world.