Do we need a gym to burn fat?

 I understand that if you want to build a specific body structure, you should go to a gym and follow the instructors. But only to burn fat, do you really need a gym? 

You can do jogging without a treadmill. Moreover, you can do physical work at home or help moms with heavy work, relatives, neighbours, disabled people, or elderly people. Even to clean or fix the neighbourhood can help your calory burns.

Then why do we have to spend money on the gym and burn fat with no benefit? Why don't we burn our extra fat by doing practical physical work?

Even a gym can produce power by using this physical strength.