Abstinence works.
Every time it’s tried.
Condoms are only a poor substitute for abstinence, but they work too, when they are used.
There was also a reason that the genitals are at the exact right distance from the length of the arm to the hand for easy and quick contact.
Actually, condoms fail regularly and don't inhibit some venereal diseases at all.
For people who use them at a high tempo and for extended periods they break apart more often than not.