Yup, both of us know people who exercise … body weight, classes, weights … who have little that we notice in physique changes for the effort. And some who do. Which means?
Yup, a pull up bar costs maybe $30 tops and will last you, well, your lifetime. A one month gym membership lasts you, well, one month. Does not include the class fee.
Again, not dissing gyms and classes. For some the money is worth it for the socialization if nothing else. Just mocking the idea that exercise is too hard and complicated for the average Joe to pull off effectively at home without a gym and classes and equipment.
A range of exercises to include all the major muscle groups with body weight is hard to design? That is simply goofy talk. Tell me what major muscle groups the simple example program I came up does not hit that say Starting Strength does. Thing about body weight exercises is that it is almost harder to not hit most of the major muscle groups than to miss them. A compound upper body pull and one push; squats; and two that hit pretty much all in concert in different ways, one emphasizing the core stabilizer muscles (the Turkish get up) and one hitting more the explosive plyometric muscles and increasing overall work capacity (burpees). Cycle through two or three sets or as many sets as you can in the time you allocate. Ten minutes is fine if you keep intensity high while maintaining form.
Designing them for your strength level? What’s so hard? Progress will be made so long as you go until the last rep is not so easy to do and doing more with good form would be questionable. Debate if you must over the extra value of 5x5 or whatever you like as most efficient (So and so has been training people for years! You don’t care what the studies say. Scientists don’t train people!) but even if so it does not mean others don’t also work well. Increase difficulty at 5 reps or 15, just increase the difficulty as you advance. Again it is very very easy: you can’t do a pull up then you jump up and let yourself down slowly until you can do a real pull up; you can do five easily, then do seven, then ten, then fifteen, then either wear a weighted backpack (books work) or start a one armed progression (you have plenty of time to look up what those are). Same exact sort of muscle response as deadlifts/squats/bench? Of course not … a different sort but same major muscle groups and more of a different sort of muscle response.
Will progression be exactly linear? No. But why do you believe that linear progression is required? Some data out there that suggests “undulating” (more random) progression works even better.
This is not precision chemistry in which exact right amounts of each exercise reagent must be added at exactly the right time at exactly the right temperatures. It is basic exercise. Use you body as a heavy thing then lift it up and put it down, repeat. Simple as that. Yes you can make it fancier and add more varieties of body weight exercises for the fun and for the challenge as you go. If you want. T-push ups, dive bombers, clapping push-ups, handstand push-ups … but the plain ole basics are a great place to start.