Ask yourself what does all life have in common? The transfer of energy. Why would the universe have all these methods of displacing/transferring energy if it’s end game is to die an inactive cold death? A big bang is just a lazy man’s theory. What we know of the universe is that galaxies are constantly colliding and recycling each other in this way. We have no idea how many galaxies there are, or what for that matter our own galaxy is heading towards. We don’t know if the universe stretches on forever, or if there’s boundaries. So much to know still.