Grayson Quay writing for The Spectator
According to the General Social Survey, the percentage of never-married Americans between the ages of 18 and 35 who did not have sex in the past year rose from around 16 percent in 2000 to over 22 percent in 2021.
There are plenty of theories, some have suggested that porn has a place to play, that it's severely damaged the minds of young men so much so that they find their sexual gratification from x-rated sites. The other is that people are so busy, they have other priorities.
I would suggest that dating app and advances in feminism mean hypergamy which still has a role to play in relationships has effectively priced most men out of being acceptable partners to a lot of women.
Grayson Quay writing for The Spectator argues that part of the decline is to do with more young American Christians choosing to not have pre-marital sex. He cites data from the Pillar, which states,
From 2000 to 2006, 40% of unmarried young adults who reported going to church at least once a week said that they also had not had sex within the last year. In the 2014 to 2021 surveys, 50% of church-going young adults said they had not had sex within a year. Among those who go to church once a year or less, the change was only from 13% to 16%.