I am not the only ex-physicist that doesn’t believe in dark matter or dark energy, or multiple universes. All of these are theoretically possible interpretations of the maths, but I do not believe they are interpretations appropriate to our universe. Like the concept of the ether, I expect they will be shown to be incorrect and replaced by explanations that don’t need such concepts.
There are already explanations for accelerating expansion that don’t rely on dark energy, such as relativity: https://astronomynow.com/2015/01/05/dark-energy-explained-by-relativistic-time-dilation/ (the title is confusing since the article explains why it isn’t needed).
My theory is even simpler and probably not original, but I can’t find any references to it on the first two pages of Google so either it’s novel or so wrong that it doesn’t even warrant mentions. Anyway, here it is, make up your own mind, it doesn’t even need equations to explain it:
As galaxies get further apart, the various field fluxes reduce with the square of distance – gravitational, electromagnetic, and so must the intergalactic portion of the Higgs flux. The Higgs field is what gives particles their mass. As the Higgs field declines, the mass of the particles in each galaxy must therefore drop too. If energy is to be conserved, then as mass declines, Galaxy speed must increase linearly with distance, as is the observation. QED.