I have done AI and I think it depends on what you pay, as with all things. I stayed at one resort that only had prebooking at 6 types of restaurant, where it was a menu option not a buffet for dinner and the meals were really delicious. Lunch was a beach bbq buffet or menu. I think it depends on the intelligence of the customer at the resort tbh. More expensive resorts that are AI just offer flexibility with a nice atmostphere. It was nice to know that we could just get small plates of food for young children, and watered down juice without paying out constantly for adult priced portions...and if children slept through lunch you could grab a snack or high tea for them later that afternoon. Otherwise you are paying £10 every day for a plate of pasta or whatever and the kids only eat a timy amount due to the heat of the day, etc.
I have been on an incredibly cheap one to the Domincan Republic when they first became the thing, about 14 years ago, and it was awful....tons of Brits and Yanks determined to drink the value of their holiday back, then complaining to the hotel that they have food poisoning after consuming 4 types of meat with every meal and 8 or so different types of dessert..then sitting in the baking sun drinking spirits and not really connecting the two!
We look at it like a safety net...breakfast is always good to have, lunch we usually do without after a late breakfast at 9.30am, then if we are too relaxed or tired to go out, it's nice to have the option of that at the hotel. It certainly doesn't tie me to the hotel, but I know it does for a lot of people.
I agree though for a lot of people this year it may be AI or stay home, so it's not really taking away customers from the competition, it's probably guaranteeing some visits to the country.