Exercise is essential for health, but not the best bet to lose weight, isn't it?
Passive exercise, that you do throughout the day, though, is a great way to expend calories. Walk more, bike for transport, use a standing desk, etc. That's the difference between 1500 calories and 2200.
Exercise is not a bad way to lose weight.
For a simple empirical study, ask every person you meet/know that is fit, and nearly everyone will say they exercise.
Specifically, cardio. If you're goal is to lose weight, you shouldn't touch weights until your BMI < 22. Just run or swim a few times a week.
Diet + cardio with no strength work can put people into 'gotta make it through this famine' mode, where their metabolism slows right down to eke out the stores as long as possible.