Is there any role today that would justify building a large single dish radio telescope to replace Arecibo? It seems that most of the modern radio astronomy instruments and observation that make the news are interferometers or phased array systems of one kind of another. Is there any application left for which a single huge dish is better (or cheaper) than the same collecting surface in the form of some kind of array of smaller dishes, whether relatively compact, like ALMA, or widely distributed like the Event Horizon telescope or the square kilometer array? In other words is there any point at all in considering replacing Arecibo by anything the same size?
Arecibo wasn't just a radio telescope, it was a radar telescope, bouncing megawatt-level radio signals off various bodies in the Solar System.  A single-dish transmitter is far superior to a phased-array or other composite system, because the beam pattern is a simple Airy disk rather than a complicated pattern formed by tens or hundreds of such disks.