For guys no limit correct, but younger males have a higher spermcount.
The female is clearly the biggest factor for your chance to conceive, but if you have a older woman + younger male it does compensate a little bit at least.

For females generally speaking untill 30 it's easy to conceive, 30-35 it's a bit harder, 35-40 it's very hard, 40-45 best chance is IVF .
Also important to note if a female was pregnant before it slows down the age factor. So if a woman has a child at 28 for example and at 44 deciddes I want another child ! it's more likely for that woman to conceive than for a first time mother. This explains why sometimes married couples have "accidental "  younger children compared to the rest of their children.

men no pause.

women have chance to conceive as long as there is still menstrual cycle.

the issue is the risk of complication in pregnancy and genetic defects in fetus becomes higher the older the pregnant person is.