It's one of those things where it gets harder to do the worse it is for you, which is unfortunate. Like, for me, I've kept myself in decent shape, I'm relatively active and fit, and my genetics so far have let me eat as much as I want without ever having to worry about getting fat, but there's people who put on weight a lot easier, obviously. As you put on weight, you become less inclined to work out, the less healthy you are, the more working out feels like a burden, and the more actual risk it poses to you. E.G. damage to your knees or having heart problems from over-exertion. So it's kindof of momentum problem.
And yes, there's scummy people who will prey on those looking to find solutions. Such, unfortunately, is life.
I wish more people had access to swimming. Swimming is a great way to work out if you're not in good shape. It's astronomically easier on the joints, it keeps you cool while you work out, it's a balanced workout, it's just great. Pools are expensive tho, and not everyone is in places where it's warm enough to do comfortable, so that's a real shame. Most important thing imho is just finding something that burns calories that you enjoy doing. Doesn't matter if it's not super efficient or whatever, the fact that you'll actually do it is the key.
There's some interesting new data about how gut biome effects cravings, too, which also leans into that vicious cycle. https://www.scientificamerican.com/article/how-gut-bacteria-tell-their-hosts-what-to-eat/
The more you eat crap, the more you crave crap, but it can work the opposite way as well.
Ultimately, calories in, calories out for loosing weight. It's not that simple, obviously, but it's a very practical approach for the vast majority of people. Also eat better food.