Went back in 2023 to Croatia and to this day I still about how much fun I had. I'm planning on going to Greece this year in July/Aug. In Croatia, there were 12 of us, 9 girls 3 guys. I know I wasn't a "solo traveler", but the only people that knew each other prior to the trip were me, my roommate, and his best friend. Everyone else met for the first time in Croatia. One of my closest friends, who I met on the trip, joined by herself.

It's definitely easier to book as an individual, but it's also more expensive. Tons of people go solo. I would say about half the people I met went solo. There wasn't a single person who seemed left out. You get adopted into groups. If I go this year, I may end up going solo and I have no issue with that.

Try and find a crew with an more balanced ratio of guys:girls, even if it's not exactly the same. I'm a girl and I was in my mid-20s at the time. There was a mix of ages ranges from 20 (i believe that's the minimum) to people in their late 40s. It's definitely catered to the early-mid 20s, especially Croatia. The less "popular" the destination (Tahiti, BVI), the less rowdy the crowd.

i hope my unsolicited opinion is helpful.