Would you rather want to wait till marriage to intimately know your partner or will you rather know everything there is before marriage?
In the old days virginity matters a lot, it was a pride for intending couples to retain their virginity before marriage, especially for the women. On the wedding night white sheet will be spread on their first conjugal night and in the morning if the sheet is stained with blood the wife will be celebrated as a virgin before marriage. That culture is no longer in practiced now, young people shy away from such cultures. They prefer to have sexual intimacy before marriage to see if they will be compatible sexually with their future spouse.
In this generation virginity before marriage is no longer important, people are free to have casual intimacies with several partners before marriage. What matters to them is faithfulness after marriage, anything that happened before marriage with other people is not important.