DH and I have cruised many times. Never been sea sick although we have seen some pretty stormy seas. I know other people have felt sick.
We do not spend for the fancy cabins. We have good repeat cruiser benefits like free laundry which makes it even easier,
In all the cruises we have done I got sick with what was either noro or food poisoning (meal off the ship.). The medical care was excellent. Doctors like to work on cruise ships to travel themselves. We had an ER doc from Ireland on that trip.
They are not for everyone, but we like them. No thinking required, very comfortable bed/cabin, and lovely crew. Yes they aren't well paid but they do get gratuities and earn more than they would at home.
We actually enjoy some of the entertainment. Some pretty good bands/singers. We love trivia and met new people.
Some are better than others. A long cruise in the Baltic was amazing. Same the Med, Barcelona to Istanbul and back. We do both ships tours and book independent ones usually sharing the price once we have met some people. You have to get up and off the ship early to meet tours. DH hates that as he loves a leisurely breakfast.
Alaska is amazing. We cruised from Vancouver. Awesome scenery, and being right in front of a calving glacier drinking hot chocolate.
It works for us. I have a chronic disease that makes me fatigued and needing quick access to toilets. Not having to drag luggage around and travel is great. The food can be a bit meh, but there are always veggies, salad, soups etc.
Don't be jealous OP, just plan a short cruise to try it out!