Reposting something I wrote a few days ago to a similar question.

The war is pointless, as the androids have nothing to fight for and (in the case of YoRHa models) are made out of the same stuff as the machines. The machines have overthrown their alien masters and are getting off the grid more and more often, if left alone they'd probably just wander about doing human shenanigans or kill themselves due to a lack of purpose, as proven by the Wise Machines. The only reason the YoRHa Project exists is to artificially prolong the war by faking human survival and the moon server, destroying all evidence proving otherwise including themselves - they even planned transmissions from the moon for years forward. Androids were created only to fight the machines, if they found out their single meaning of life had no purpose they'd be useless. They can't just "move on". They'd do the same thing the Wise Machines do. Through YoRHa, the memory of mankind long gone lives on. Glory to Mankind.