This is a very valid point. A few days back I had to rearrange my kettlebells to a different place at home. So I just carried them. Given how difficult it was walking while carrying them(Heck it was even hard getting up lifting them), I went like There is no way Im carrying this kind of weight on my body.
The example of a person with a musculoskeletal system conditioned to carrying around a 60 kg body, but weighs 120 kgs is basically competing in a Olympic powerlifting competition like situation to just do basic tasks(Using toilets, walking for everyday life tasks).
I can only imagine how hard and near impossible task it is for some one to be exercising everyday.
“Just ride your bike” is an easy solution for someone who is already normal weight but it’s not nearly as easy for someone who’s overweight.