Do you agree that body weight training is an essential foundation on which to build overall fitness?
I would even start an advanced client with body weight exercises to check their form before trying any external resistance. If they can’t do 15 reps of any bodyweight exercise, I know there is no point in adding weight to a similar movement because they probably wouldn’t gain any advantage from the weights. After they can do 15 reps I add a few pounds and work to increase reps before I add any more. For exercises that have no body weight equivalent, I would start as light as possible.