Have never been to one, but often choose itineraries and ships that do not appeal to families.
Have been to Canary Islands with Azamara - only one baby on the ship.
Went with Regent with some teens, but neither Regent nor Azamara have “kids’ stuff”
I have thought about trying Virgin, but the itenararies are short and seems to be repeated trips…When I have made searched.
lets hope for more options for adults only in the future