Actually, fresh veggies and the time to cook them are harder to get and more expensive than fast food in many places across at least America. Look up the concept of a "food desert". There's a reason the US has an obesity epidemic, and it's not just because people got lazy.
Imagine working two and half jobs, 80-90 hours a week, in a place where fresh food is not readily available, even if you had the time and energy to cook. It's very easy to develop bad habits, even if you don't want to, and especially when a lot of food in the US is specifically crafted to be as addictive as possible.
Obesity isn't just about being lazy. There are a lot of reasons obesity is rising in most of the world, but especially in the US.