Long term success depends almost exclusively on making good food choices and not so much the restriction of the surgery. The surgery gives you a window of time, generally 12-24 months where you can reboot your relationship with food and build new eating habits to maintain long term weight loss. You can certainly gain the weight back after any weight loss surgery if you make poor food choices. There are several reasons why it is so difficult to lose weight "naturally" especially after a person enters the "obese" or "morbidly obese" range. I'll sound like a broken record for those on here to who know me well, but I'll share some of the science behind it.
First, our bodies are designed to protect weight and not lose it. For as long as humans have been on earth, there has only been a plentiful food supply for a very, very small fraction of that existence. Our genetics try to protect us from starvation on several levels, but there is one hormone that seems to have the greatest impact that causes obese people from keeping weight off after they lose it.
The hormone leptin is stored in our fat. When we are obese, we obviously have a lot more fat in our bodies and therefore much more leptin. When we lose fat, leptin is released into our blood stream and goes to our brain. It triggers two primary reactions. Your brain slows your metabolism and increases your hunger. This effect is actually increased the more fat we lose, so while we will have some effect if we lose 20lbs of fat, then second 20lbs of fat will actually elicit a stronger response to the leptin. This continues to occur as you lose fat. You body wants to slow your metabolism and it wants you to eat high calorie foods. It is very hard to resist, and it is why so most people regain their weight on "yo-yo" diets. Your body is driving you to get back to the weight it was prior to the attempted weight loss. Now, there are some lucky unicorns out there who are able to do it, but it's rare. If it was easy, there would be far fewer obese people, and the weight loss industry would be very small instead of what it is today. Most people fail, and repeat, and fail, and repeat. Most people who do reach their goal weight "naturally" have to eat less and exercise more to keep it off than a person of the same weight who was never obese. As soon as they slack off from that, the weight usually piles back on. Again, there are always a few who are able to do it, but it's not the norm.
That's not all there is to it, but it is a huge part of why it is so difficult. The amazing thing about the surgery is that it actually helps you bypass that leptin response. It doesn't try to "protect" your heavy weight and your brain doesn't receive the mass leptin signals that it would have received without the surgery. Scientists don't know for sure why this side effect occurs. It's one of several side effects related to hunger and the microbiome that they are studying. The restriction is only a small part of the reason people lose weight. It's pretty fascinating stuff. The University of Michigan has a great obesity research department that is exploring the side effects of surgery that have this profound effect on our biology.
So, what does that mean for us? It means that most of us can lose a lot of weight over the course of a year or so and our bodies aren't going to fight against us too much. However, that doesn't make it easy. The surgery doesn't help our coping mechanisms for stress and other emotions or food addictions or other psychological issues that might drive a person to make poor food choices. We still have to learn to battle those demons like everyone else, but generally the ability to lose weight fairly quickly after surgery allows us to concentrate a bit more on ourselves and maybe learn to deal with those things better. Some of us seek professional help, some of us self-help, and some of us just cruise along and never look back. We all have slightly different stories and experiences that lead to our obesity. Likewise, our experience transforming back to non-obese will vary from person to person.
If you've dieted and failed more than once, the cold hard truth is that you are unlikely to be successful trying to diet again. It's not because you lack willpower, but because your biology and brain will battle against you, and it is a very difficult war to win. It's possible for a few, but the surgery is such a great tool or "weapon" in the fight. It's not to be undertaken lightly, but it is by far the best chance for success both short term and long term IF you commit to making good food choices moving forward with your new body, otherwise, if you just think you'll be fine eating the same stuff but in smaller amounts, it will probably just lead back down the same road to obesity in the future. That being said, your chances for long term success are much greater with the surgery than without.
As far as cravings go, everyone has a little different experience with that as well. Some people's tastes change significantly. I'm on almost a 100% plant based diet and I never thought I'd do that, but it's what I crave now. I still eat some meat, dairy, or eggs every now and then, but I don't crave it. I don't crave fast food like I used to. I still have a bit of a sweet tooth, so I have to keep that out of the house, but I'm also more sensitive to sweet, so I generally it generally takes less sweetness to satisfy me.
Some people still feel like they get as hungry as they used to before, and some feel like they aren't hungry enough. Sometimes your brain can play some tricks on you, but overall I think most people experience far less hunger for the first year, and as I mentioned earlier, that is the window of time when you can really focus on building great new habits with food.
I still really enjoy my meals and I do a lot of cooking and still enjoy that. It hasn't diminished anything for me as far as culinary delights go, I just have to get used to different serving sizes.
So, it comes down to what sort of quality of life do you want and are you willing to change your food habits a bit of long term success? You can still enjoy eating, but it will need to be a little bit different. The surgery will give you an amazing tool to succeed, you just need to use it to it's full potential and reap it's benefits when they are the strongest.
Best of luck no matter which direction you go!
