Astronomers chose what they believed to be an empty chunk of sky to survey. If there are that many galaxies in such a tiny, empty piece of sky, then how do you suppose that compares to the number of galaxies that are more readily visible?
Less than one percent.
Do you need me to draw you a picture?
Yellow represents the UDF. Red represents the rest of the area that would fall under the "barely visible category". Blue represents the rest of the visible universe, or "more readily visible" area.
Ok, you're being inconsistent now. For three reasons, actually.
1) If yellow is the "UDF" and blue is the universe, then what is red?
2) Why the hell is the universe blue? Do round earthers now think that the universe is blue?
3) The UDF has to be a fabrication because it is impossible for a telescope to fly in space for that long.
Please think before posting.