There is a time and a place for fake corals, and it is all down to the owner. But don't for a minute think it will look that good without effort. I worked at an aquariun with artificial corals, and much of my job was climbing into tanks to nearly constantly scrub the algae off. The particular fake corals used did not have color all the way through, to then the color came off and overall they looked like crud.
Moveable pieces can be removed and easily bleached at regular intervals - which is what many restaurants will do to keep them looking good. IMO it is what needs to be done.
IMO, some of those corals look extraordinarily artificial and so I, personally, do not like those pictured above. That is just not realistic. It is up to the owner...but eh. Not to mention it would compete quite a lot, IMO, with the beauty of the fish themselves.
Do not overlook the benefits of natural live rock to larger fish like angels and tangs. there is no doubt whatsoever that it provides a more natural habitat for them - more realistic grazing and seems to reduce stress.