You don't have to exercise to lose weight, you don't even have to drastically change your diet.
Eat. Less.
You can lose weight on a diet of pizza, donuts and laying on the couch if you simply eat less calories than you burn.
You quite frankly sound like one of the many enablers that wants to make every excuse possible about why it's impossible to lose weight rather than taking responsibility for the countless poor eating decisions that lead to obesity. No one is born fat and no one wakes up fat, take responsibility.
Of course not and that's not what they're saying. They're saying that trying to outrun a bad diet is never going to happen.
You could run a marathon every day and then still gain weight because you ate three birthday cakes, five burgers a bucket of fries and a whole pizza for breakfast , lunch and dinner.
Enablers hate admitting it, but weight is lost in the kitchen.
If you want to lose weight, eat less, if you want you can also get fit. That's the difference between being a healthy weight and being fit and healthy.