But after a while there’s enough “fog” in between you and the spot you’re looking at that you can’t resolve anything, no matter how big your telescope is. You can’t look through a cloud just by getting bigger binoculars.
And information from light is quantized, it can’t get any smaller than one photon. At some distance that one photon you need to image the body never intersects your detector, either because it got absorbed/deflected along the way, or the body is too faint and too distant for even one photon to travel between the body and your detector over the detection period.