[strken]

I think the point is that a regular body weight routine is harder than using weights. If you're sedentary, doing a push-up is like starting out with bench presses that are more than half your bodyweight, finding an inclined surface to do push-ups against is not always possible, and using your knees can be painful, whereas if you're in a gym you can go bench press the 20kg bar or lighter dumbbells and know exactly how much weight you're using each session. Doing a chin-up on a tree in the park means you can't grab an assisted pull up band or use a machine to help you, so you're stuck trying to scramble up the tree with your feet + use bad sideways technique then lower yourself down slowly, which is risking injury.

These concerns are especially relevant for the elderly.

[alamortsubite]

By the same token, a lot of sedentary people with no lifting experience might be intimidated by the idea of going to a gym, and the cost and even just the step of getting to a gym are additional barriers they have to overcome.

Getting started with a body weight routine or simple bands or kettle bell setup at home has huge advantages.

[anotherevan]

Just a note that swinging kettle bells, à la the simple and sinister book caused medial epicondylitis for me (buggered up the tendons in both my elbows). This is taking a long time to heal and limiting options on other exercises I can do that involve even a moderate grip.

My recommendation would be to rent a rowing machine and try that first.

[stvltvs]

To each their own, of course, but there are lots of ways to modify bodyweight exercises to accommodate even the most sedentary. I wouldn't exercise half as much if I had to go to the gym. It's less convenient for my WFH lifestyle and more expensive.

Edit: I should also say that I use weights like dumbbells and kettlebells at home. Not needed to start out, but very helpful.

[ricc]

Both options will require some research to tailor fit which progression level works best for an individual. Taking push-ups vs bench presses as an example, knowing that one can start with either wall push-ups or an empty barbell, I reckon the wall push-ups has much less friction than the other.