Earlier quoted context omitted.
If you've decided you don't want any (more) kids in the future, a vasectomy is the easiest way to insure that with the least likely side effects for anyone. Why would you force your wife to be subjected to the side effects of birth control if you can get a simple out-patient procedure?
Because why would you do something essentially irreversible when the other party has a temporary solution. I’ve changed my mind about things plenty of times, why would I do something I regret 20 years from now.
But everyone has a point after which they decide they don't want more kids and it's insane to force your partner to continue being responsible for that with all the downsides when you can just get a snip.
And if you're thinking you're gonna want kids 20 years from now as a man in his 30s or 40s or later, run that by your partner and see what she thinks about that.