Epicycles were brilliant math, as a model of our view of the universe. Crystalline spheres were lousy physics, as explanation.

The problem is the models become the center of attention, then the crowd builds schools around them.

No matter how many people are involved, "shut up and calculate" is still, "garbage in, garbage out," if the underlaying premises are flawed.

Consider that when they realized that cosmic redshift increases proportional to distance in all directions, it either meant we are at the exact center of the universe, or it was an optical effect.

Given there didn't seem to be any other disturbance to the light and thus cause for it to be "tired," the argument became that space itself expands, because of Einstein's "Spacetime," as the physical explanation for the math of Relativity.

Completely ignoring the central premise is the speed of light always being Constant.

Such that if space were to expand, the speed of light should increase proportionally.

Instead, two metrics are being derived from the same light. One based on the speed and one based on the spectrum. If the speed were assumed to be the numerator, it would be a tired light theory, but as an expanding space theory, the speed is still the implicit denominator. The "ruler" against which this expansion is being calibrated.