Welcome to "The Last Tango of the Finite Graviton".
It is amazing to imagine all the stars in the galaxy and all the galaxies in the Universe and remember that our naïve analogue understanding of the Universe leaves us failing to understand dark-matter or how a single star in the entire Cosmos ever gravitationally condenses into existence in the first place.
None of this was Einstein's fault. When still very young, the poor child's mind was hypnotised by so-called "mathematicians" into counting things using an over-simplified version of number-theory that works fine for classical mechanics, but is completely useless for counting the Relativity of Nature.
Everything in so-called "cosmology" that depends upon the Special Theory of Relativity, as we presently interpret it, is hereby compromised with extreme prejudice. The Universe is exponentially older than the absurd three-Earth-age (i.e. instant-creation v2.0) figure that we come up with using the rotationally-frigid flat-earth-arithmetic of classical mechanics. With the Cosmic Microwave Background image we are observing galactic core-body cross-firing at a range of 295 billion light years off, 295 billion years ago. At that time, the Universe was already not less than 10^80 years old. The deep space red-shifting is caused by a macro-gravitational optical illusion of exponential apparent scale decay. The 13.8 billion year figure that we came up with is just the time-constant of the exponential energy image decay.
A big bang? Most definitely, but about 21 times further back in time than previously thought and definitely not creating any new matter. As its warm core becomes ignited by the cross-fire wave, each galaxy destroys about 98% its matter. Heavy debris from these eruptions falls in to form the so called black holes. Comparing a modern supernova to a single galactic core-blast is about the same as comparing a single toy pistol cap going bang to
Castle Bravo. How close can one get to a galactic core-blast and survive? That's the easy one, one needs to be say 295 billion light years away. The globe of cross-fire probably still continues to this day, now passing out through almost 1.2 trillion light years in diameter. The initial ignition probably occurred by two young warm galaxy cores colliding. This must have happened quite close to our own galaxy because we are rather close to the centre of the CMB. That would have happened locally at two times 295 billion years ago or 590 billion years ago, of course.
Background photo; a highly distorted view of "the Great Jewels of the Pleiades", at this trivial magnification, all distant stars are actually represented by single pixels of light.