You don’t have to be throwing your body down or going as fast as possible for it to be effective. The key is to to what your body allows.

You can slowly get down to your hands. You can use push up bars if your wrists have issues (I do this). You can move your legs back one at a time if you are unable to jump them back. You can return your legs to a squat position one at a time if you are unable to jump them forward (I do this to protect my back). And you can go at a slow and steady pace if you are unable to do the movements fast.

I agry that people don’t need to do the fast pace of those CrossFit people because that could lead to injury. But carefully doing the movements is a great full body workout. Legs, chest, shoulders, arms, abs all get some work.