Just because you can have an erection and produce sperm at 70 doesn't mean you can have children and if you do they'll most likely suffer from down syndrome or other conditions.
Having kids after 45 as a male carries risks for the children as well.
Please cite something for this assertion or delete it, as it is not in line with anything I've read on the matter.
Increased paternal age carries some potential for increased side effects for their children, but it is absolutely nowhere near the risks involved in a delayed pregnancy for women [0].
[0]https://www.nytimes.com/2018/11/07/well/family/older-fathers...
An order of magnitude higher chance of genetic defects isn’t very significant when the initial risk is less than .1%