Independence vs newer ships

My wife and I just recently went on a 4 night cruise to Labadee on Independence of the Seas (it was our first Royal Caribbean cruise and my wife’s overall first cruise), and we thought it was pretty great. Some of the food missed here and there and there were a couple little issues here and there but overall it felt like a great vacation for a pretty cheap price- significantly cheaper than the newer ships. We got a balcony state room and were happy with the experience. We talked to some other couples who thought it was only ok and that we should try oasis class. So my question is this: is there that much of a difference? In what categories do the newer ships really shine? I wouldn’t necessarily expect food to be better for example. And then, what ships in what classes shine over other ones? I know this is a lot, but I find myself super curious about Royal Caribbean and cruising in general lately. Thanks in advance!