You are missing the point completely. Has nothing to do with puritanism. Porn addiction is actually sex negative, it causes people to isolate themselves and become less likely to pursue relationships, choose to get married and have children, etc.
It causes people to enjoy porn more than real sex because it is risk-free, dynamic, and always available. Not a coincidence that with the rise of internet pornography we are seeing declining birth rates around the world.
Porn has little to nothing to do with lower rates in marriage and lower fertility rates.
The main reason for that are economic issues. Less and less people are now able to afford to have kids.
There is also a big change in our society structure, as in a couple of centuries, we went from a mostly rural society, to a highly urban society.
Kids in rural societies, were also a source of work in the fields. But in the cities they are just an economic burden. And with school years increasing so much, it really becomes expensive.
But the real issue, is that wages did not improve in scale with this change. Quite the opposite, in most countries, real purchasing power has decreased.
Another issue for men to not look out for marriage, is that it's a highly unbalanced situation for men.
Divorce rates are extremely high, most developed countries have divorce rates above 50%. Some as high as 70%.
Do you know who starts divorce procedures the most? It's women. For example, in the USA, 80% of divorces are started by women.
And the justice system always takes the side of the women. So when a divorce occurs, usually the men loses the house, the kids and has to pay alimony for over a decade.
It's a terrible deal for men. So why do it, when the chance of failure is so high and the consequences are so disastrous.