Scale matters for massive thermodynamic processes for effieiceny, but 21st century technology has become much more decentralized. You don't need massive installations of solar or wind at one location, the can be distributed throughout the grid. Massive scale is possible, but it's not required once you get away from heat differentials as the core of your energy process.

It still matters for transmission, construction and maintenance costs, as well as resources like land and labor.

You may not need scaled installations, but they will still beat out the alternatives in any industry shakeout over the long term. We build large scale factories, farms, ports, airports, roads and retail outlets. These happen because they work. Even if the energy production at scale gave no advantage, all the other advantages of scale means that it wins out in the end.