The quintic transitioning to cubic is the theoretically-available information, assuming that object-space is temporally-invariant aka not detectably varying on time scales shorter than our total assumed collects, for each/any/every targeted field. For nearly all traditional amateur observations, this is the case. To the extent that is valid... this means that, although it may take a long time to survey the entire sky, if one is patient, he ultimately realizes the quintic-cubic advantage; big tortoise inexorably winning the arbitrarily long marathon, over any smaller hare. Unlike the professionals, we guys embrace astronomy as a casually-paced, relaxing hobby, so max burn rate ostensibly takes a back seat to the pleasure of embracing the Cosmos, on Mother Nature's terms. At least that's the working model of the avocation.
I know, I know... in actuality, many of us get impatient waiting for those sparse photons to come lazily drizzling down the tube and into the detector array... so information rate, which goes quadratic with aperture and quadratic with field (aka, rigorously étendue) takes precedence. And, no coincidence... Emmy Noether's Theorem formalizes that invariant. So, in the limit, we craft bigger/faster systems and fly-eye hyperhemispherical parquets, giant cryo max QE gigapix arrays, to suck in information as much and as fast as possible.
And yet, the quintic/cubic ceiling remains, despite all that --- as the limiting arbiter, regardless. Bigger will always win, given enough time... [Martin Harwit's Thesis covers all this kinda stuff. The nifty thing about his Gestalt is that our minutia computations that we routinely labor over, in no way alter that invariant conclusion.] Tom