To some extent. Otherwise one might ask how it was they had such a hard time finding funding over recent years.
FAST is in many ways a much more sophisticated instrument. It has not just greater collecting area but also a fancy system to reshape the dish. At both sites lots of work has been done on receivers, developing multi-beam or phased-array systems. But, what FAST doesn’t have is transmit capability. That leaves more work for Goldstone but of course that does not have the range of Arecibo.
Interferometers are great, but they don’t have the sensitivity on the angular scales that a single dish has. A big instrument like Arecibo (or other big, but not that big, dishes like the Lovell Telescope, Effelsberg or Green Bank Telescope) has lots of sensitivity on broad angular scales – angular frequencies down to dc – meaning they can make absolute power measurements, which interferometers can’t. Sometimes that’s what you need.
SKA will be hugely important (and SKA pathfinder instruments already are) but it certainly won’t do TX.