Constant expansion means it’ll never reach all parts and stuff just regenerates
Albert Lombard 17, Senior Systems Engineer and Sales and Marketing Manager at GEW Technologies, BA in Electrical Engineering from the University of Pretoria, Diploma in Datametrics, Computer Science, and Information Technology from the University of South Africa, “Can Something Human-Made Destroy The Universe?”, Quora, 6/30/2017, https://www.quora.com/Can-something-human-made-destroy-the-universe
Hard to imagine. Just to get a gut-feeling. Our milky way galaxy has between 100 and 400 billion stars. The current consensus is that the average star count is about 100 billion (10^11) stars per galaxy (somewhere between dwarf galaxies with a few billion stars and supergiant galaxies like IC1101 that has 100 trillion (10^14) stars). Now if the galaxy count of the Hubble extreme deep field is extrapolated over the entire celestial sphere, one comes to 100 billion galaxies, however there are recent findings that the estimate may be out be a factor of 10 so there may be 1 trillion (10^12) galaxies in the OBSERVABLE universe. So if you make the sums, it is estimated that there may be about 10^11 X 10^12 = 10^23 stars only in the OBSERVABLE universe. Also the estimated size of the observable universe is 93 billion light years in diameter (46.5 billion light years radius), giving a volume of 4.2X10^32 cubic light years!
Now given the unimaginable feat of destroying even one star, can you imagine this tribe of hairless apes destroying 10^23 stars spread over a volume of 4.2X10^42 cubic light years?! Oh yeah, and even if they can destroy stars and travel at the speed of light, after traveling 46 billion years to get to the edge of the observable universe, it would have expanded by another few billion light years.
And another thing, in the wake of the trial of destruction of the hairless apes, the gas and dust of the destroyed stars will just collapse and form new stars!