I think you're missing the point. You use something like this to help in design/testing of accessible spaces. An exosuit can't cut you half to help you make better children's spaces.
Additionally, assuming you're not already geriatric, simulating it is the only way to experience it short of waiting. If you're an adult, you were already a kid at some point.
Floating the idea of a youth simulator (like a VR app with integrated exosuit) could be used to measure physiological and cognitive age gaps. It might be valuable for science and medicine, but also for things like understanding empathy/social knowledge or understanding workflows/applied knowledge.