I worked on a cruise ship below decks, once, for 3 hours, and I swore I would never take a cruise. Take the dirtiest hotel you have ever been in, and then ensure you cant leave it for days at a time. It interests me that demand is increasing but I suspect thats just good advertising.
Decades ago I took a couple of Carnival cruises.
Things are not better now. What a shitshow. Royal Caribbean sucked, but Norwegian was a new low. The only word that describes both the en-route experience and the destinations is DISMAL.
At least Royal Caribbean had a pleasant food-court type of dining area, with stations of verious kinds in a dispersed layout that was navigable. Norwegian had only a narrow "racetrack" going around a central core, with serving stations in the wall. It was only a few feet wide, which meant you couldn't move because it was blocked by scooters (a totally predictable situation given the demographics of cruise ships).
Then there was the smoke. WTF. We had an upper cabin with a balcony. Doing 20 knots on the open ocean, we couldn't hang out out there because it was continually inundated with cigarette smoke... and not even from the immediate neighbor. It was mind-boggling. There was also a smoking area right next to a sushi restaurant. And you had to walk through the smoke-ridden casino area on every deck to get anywhere on the boat. At least Royal Caribbean kept that whole giant ashtray confined to a central area on the lower level. Totally fine.
Cruises are absolute shit. You're way better off just going to an all-inclusive resort somewhere, even somewhere cheap.