I guess some people feel lonely/don't have friends who share their interests or can take the same amount of time off. The influencers that lead the trips seem like a friend, since you follow their daily lives. It probably feels safer and more fun than joining a totally random group trip. Seems being the operating word since these people often don't have any real qualifications to lead the trips they do. But I do get it. As I go into my 30s, more and more friends get married, pop out babies. Their holidays are now being used to travel with their romantic partners or families, not with friends. I actually like traveling alone so I'm not very fussed, but some people hate it or are scared of it. So for single people with disposable income who don't want to travel alone, trips like this sound like a good option even when they're more expensive.
That said, why on earth is anyone willingly paying a trip that puts you in the vicinity of Zanna, tallest and most annoying human on earth?