I’ve heard it said that the angular size of many astronomical targets is not so small — that the real limit to seeing them is the overall amount of light collected.

But then some basic sense of scale eludes me: 1) isn’t most astronomical stuff insanely far away, to the point that it would have to be cosmically large to take up a medium angular size? 2) the angular “real estate” in the sky is severely limited (4pi solid angle) so wouldn’t this get quickly used up such that we could only see a small collection of such objects? (Andromeda is already taking up a huge patch of the night sky!)

Of course these are quantitative questions that can be settled by calculation, but does anyone have relevant intuition to offer?