Actually basic logic contradicts the Big Bang Theory.

When they discovered that cosmic redshift increases proportional to distance in all directions, it either meant, with conventional doppler effect, that we are at the exact center of the universe, or that redshift was some form of optical effect, aka, tired light theory. Given there didn't seem to be any medium otherwise influencing the light, tired light was dismissed.

So it was argued that space itself expands, based on Einstein's theory of a "fabric of spacetime" as physical basis for the Math of Relativity.

Yet the central premise of that idea is the speed of light is always measured as a Constant. So if space were to expand, the speed of light would have to increase proportionally.

Yet what is argued is that light speed remains otherwise constant, but the universe/intergalactic space expands.

So two metrics are being derived from the same light. One based on the speed and one based on the spectrum.

If the speed was the numerator, it would be a tired light theory, but as an expanding space theory, the speed is still the implicit denominator. The metric by which this expansion is measured. Essentially Einstein's "ruler."

One way it has been shown that light will redshift over distance, is as multi spectrum "packets," as the higher frequencies dissipate faster, but that would mean we are sampling a wave front and the quantification of light is a function of its absorption and measurement. Essentially a loading, or threshold model.

Which would not go over well in some schools of thought.

What they were arguing over, with the Hubble;

https://www.americanscientist.org/article/modern-cosmology-science-or-folktale