All diets work for losing weight as long as you ingest less calories than you expend, pretty simple math. Anybody who thinks there is something "magical" about the keto diet that allows you to lose weight by ingesting more calories than you expend doesn't know much about how the human organism works.

That being said many like Keto because it's simple to understand (don't eat carbs), drops initial weight faster than most other diets (a lot of water from lack of stored glycogen) and fairly easy to adhere to if your are fairly strict and dedicated. Has the same problems that most "diets" have in that most people do not commit to the lifestyle permanently and when they lose the weight they revert back to old eating habits and gain the weight back plus more. It is not fool proof either, some people love meat and if you tell them eat as much as you want some will actually gain weight while remaining in ketosis. Furthermore, it has yet to be seen if it is the most healthy diet long term or if the high levels of fat intake and lack of fiber and micronutrients from carb sources causes health issues in the long term.

I wouldn't suggest anyone adopt the keto lifestyle permanently unless it was the only way they were going to lose the weight and stay at a health weight (healthy weight keto lifestyle probably still healthier than staying over-fat).

A diet which consists of eating the appropriate amount of calories for your goals (maintain, lose or gain weight), consisting of a variety of mostly whole foods (meats, veggies, dairy, grains, fruit, etc.) is most likely the best diet long term, but most people will not commit to living this way. It's really not that hard, you can still drink alcohol, eat junk food, etc. just keep it under about 20% of your total diet. In other words, eat like adult.