Women are born with their supply of eggs, so they are more ‘pristine’ than any other cell. Sperm are generated continuously throughout life, and there is evidence sperm quality decreases over time. Some diseases associate with increasing age of the father (autism, schizophrenia). The effect takes hold mainly after paternal age 40. Having said that, I recall there is some work showing sperm generating cells are kinda special in that they don’t develop as much mutational damage as other cells. Does make you worry though that progressive generations of older and older fathers may lead to some kind of problem. With rates of assisted fertility increasing, perhaps 16 yo boys should bank sperm for the future.