I don't think it's a s simple as inactivity. IF this were true, then being active would reverse the weight gains, but it does not, at least not for me and others. I was still as active in my 30s as I was in my late teens and 20s but still gained weight. Likewise, gyms are full of people in their 30s and 40s who are not losing weight despite regular attendance. Despite the popularity of fitness apps, people keep getting fatter. It is only GLP-1 drugs that has put some dent in obesity rates. I think metabolism or some other biological, non-environmental variable plays some role. Or some reduction of NEAT that cannot be explained by careers.
On average man burns ca. 2500 kcal per day, mostly in rest. One hour of reasonably intensive cardio burns 500~600 kcal. If you have two such workouts a week it comes down to an increased energy use of 2*600/(7*2500) = 7%. Or a large meal. Just looking at the numbers it seems spending some time at the gym is not going to do much for loosing weight. Or said differently: eating 7% less is easier.
Of course cardio and strength training are useful for building/preserving muscle mass and general fitness. But for weight loss looking at food seems more effective.
If that is true it is no surprise to me all sorts of folk medicine work on warts.