Outdoors on cell towers, yes. Not that helpful indoors. Reflections dominate. Diversity antennas are more useful indoors, because it's rare that both are in a reflection null.

more than 10 years ago some company was doing adaptive beam forming WiFi routers/switches, and what i remember reading about them is that actual direction of the beam for a given connection wasn't necessarily the geographical straight to the other end of the connection, instead it was whatever direction was adaptively found, and that frequently meant very non-straightforward mulitply reflected path. The beauty was that beam power at the "total multi-segmented reflected/bounced" length of the path could still be much higher than onmidirectionally transmitted power even at the lesser distance.

Can you do that without moving parts?

Yes. Phased arrays are just that.

Not very power efficient, though.

Nor space efficient... (depending on the wavelength).