Why can't we see light from beyond the observable universe?
I've done a lot of research on this and all I've found is unsatisfactory answers and straight up nonsense.
Some claim that the universe "expands faster than the speed of light" beyond the observable universe. Such a claim doesn't even make sense because the units of speed are m/s and for expansion are Hz. That's like saying "the area of this square is larger than the volume of this cube".
All that the expansion can do to light (as far as I know) is redshift it. And light doesn't have a minimum possible frequency or energy value. So even if the expansion of the universe is very rapid, why does the light of distant objects "never reach us". Surely it still would, just extremely redshifted. In this case it does still reach us, and yet the claim is that it cannot.
We often detect redshifted light, and that light has not been slowed down. When we detect it, it still goes at c, even though (in fact a better word than "even though" here is "because") it is redshifted. Light is always propagating at c no matter the reference frame.
More precisely: does the light really never reach us, or can we just not detect it?
If it never reaches us - why?
If we cannot detect it although it does reach us - why?