Radio telescope dishes are huge so that they can receive (or even transmit in the case of Arecibo, which is gone now) a narrow beam. At long wavelengths you need something huge to get a narrow beam.

But you can also use multiple, much smaller antennas to synthesize a narrow beam, and those little antennas are often dishes but can also be very simple and rather small antennas.

interferometry is good for seeing small objects, but not faint objects. for faint objects there's nothing that works better than a giant dish