According to Wikipedia's List of the most distant astronomical objects, the most distant galaxy (GN-z11) is estimated to be around 13.39 billion light years away from earth.
However, the observable universe has a diameter of 92 billion light years. I understand that galaxies needed some time to form, however I'm a bit confused by the fact that all of the objects are within the radius of 13.8 billion light years (which is the age of the universe). To me, it would make more sense if some objects would be also 20 or 30 billion light years away.
Are our telescopes simply not good enough to receive light from such far away galaxies or is there any "rule" that prevents galaxies to be farther away than the age of the univere in light years?
Also, if the second is true, how can astronomers know the universe is actually 92 billion ligt years across?