I think there's a growing realisation that you don't always "need" a boy/girl friend and people are starting to be more choosy, and can have a happy social life not revolving around always having a partner. It's all about freedom these days, especially among the young. Especially among those with higher/further education who know they have choices and career/lifestyle options.
My son is 23 and doesn't have a girlfriend, and no, he's not gay, he just doesn't want the drama as he calls it! Several of his graduate friends (from Uni and work) have the same outlook and opinion. They're in no hurry to get married and have children as they want to "live" as they call it. They want the freedom to go to football every Saturday, or to go for "lad's" holidays, or pub quiz nights, etc., together with no obligation, no drama, etc. He has different "groups" of friends, some from work, some from Uni, some from his home town, and just loves to "flit" in between different groups, no obligation. No tantrums or sulks if he doesn't fancy football one weekend, or wants to go to a pub quiz with his work group instead of his Uni friend group, etc. Of course, some of his friends have partners, long and short term, but they also have relatively long gaps between partners - they don't just go out on the pull to find a new partner the day after a break up - they just chill out, enjoy the single life, and then if someone comes along, then fair enough.
Both me and OH have said that we'd not be bothered about getting a new "partner" when one of us dies. I certainly wouldn't start going on dating apps, and he says the same. We'd be fine being single. Maybe if the "right" person came along, I'd consider getting involved, but I wouldn't be going looking for someone.
I think the days are long gone when you "needed" a partner due to financial, social or practical reasons. It's now socially fine to go places on your own, we no longer have separate traditional "male/female" roles. Both sexes have similar job/career/earning opportunities.