I had a vasectomy in 1977 after 2 years of marriage, no children. My wife was having birth control issues with the Copper 7 IUD possibility of uterine puncturing and birth control pills were not as good as they are today. And she did not feel comfortable with the idea of having children as her family upbringing wasn't the best. Years later, after her sister died of colon cancer, we took our nephew and niece in for three summers, I did the fathering and the mothering as my wife could only handle the cooking and cleaning and an occasional story book. She would not have done well with having her own kids.
Do I regret it? No. If for some reason I had lost my wife and remarried, I would have considered trying to father children. Since that didn't happen I will probably never have children as I am now 59.