Why the hell does everyone bring up calories for fat loss? I lost 45 pounds by not counting my calories at all (only in the beginning, when I didn't know any better). You lose fat by reducing insulin resistance, not by food intake. I didn't even exercise, I basically sat all day and those pounds flew off. I did intermittent fasting, learned to cook, and slowly started replacing my diet with healthier foods. I'll be honest, I lost a good portion by going keto and avoiding the majority of carbs but I quit because there's no way I could keep a diet like that long-term. Now I eat complex carbs and indulge in junk food once in awhile, with my diet being mostly whole foods. I keep a steady 150ish at 5'8.
The more important factor is ALWAYS the psychological factor, which NEVER gets brought up in weight loss advice. If someone is obese or nearing obesity, they have a food addiction. They keep eating because they're filling a void in themselves. I'll be honest, I had to deal with it and if you're overweight and trying to lose weight you'll have to deal with it too. When I was overweight, I was also depressed and in an abusive environment so I ate the pain away. It's related to emotional nourishment, which unfortunately not many people get enough of these days and it fuels food addiction. It fuels any addiction, really. Most likely there's no one around the obese person who understands them and has any type of real, deep connection with them as a person so they eat to keep that void away. At least that's what it was for me, maybe it's different for someone else. That's the real reason someone can't lose weight, there's an underlying psychological problem fueling it. No mentally healthy person is overweight. No amount of "calorie counting" will solve the empty void someone who's obese is trying to fill.