The cake BigBang is a lie.
original source :
https://iopscience.iop.org/article/10.3847/2041-8213/ad1ddd

see also :
https://en.m.wikipedia.org/wiki/Hubble’s_law
Hubble tension
In the 21st century, multiple methods have been used to determine the Hubble constant. “Late universe” measurements using calibrated distance ladder techniques have converged on a value of approximately 73 (km/s)/Mpc. Since 2000, “early universe” techniques based on measurements of the cosmic microwave background have become available, and these agree on a value near 67.7 (km/s)/Mpc. (…)
(…) The most exciting possibility is new physics beyond the currently accepted cosmological model of the universe, (…)

Seeing the universe expanding at different rates could just mean we’re not as close to the center as we thought, and the parts further away from the center are moving faster. That’s my layman’s hypothesis though

Why couldn’t this still be “big bang”? Look at a grenade for example. When it explodes, a shock wave expands from it in a near perfect sphere, but the fragments previous packed inside of it explode out at different speeds depending on their mass.

If you were in the center of that explosion, measuring the speed of fragments traveling away from you, they’d travel at different speeds. Only the initial shockwave would be constant.