Au contraire, it is a very simply observed and reported fact, famously seen by experimenters who were not even looking for it, even though there were those who WERE looking for it, just a few miles away, albeit with inferior equipment. Such is fate.
Oh, I know CBR exists and can be measured along with Doppler shift measurements in all directions. Scientists can have a theory about what caused CBR, but they will have a hard time absolutely proving it was a big bang since they cannot observe it happening.
I have not seen any recent papers on Doppler shift looking at galaxies in all directions. I thought that everything was moving apart so that could point to a central point. But it seems local galaxies are moving toward the Great Attractor region so all galaxies are not moving apart.
It takes approximately 225 Million years for our solar system to make one revolution around the Milky Way Galaxy.