FYI Hack Club helps fiscally sponsor organizations that do not have the capacity to apply for nonprofit status (https://hackclub.com/fiscal-sponsorship/). The 7% income covers dev fees for lawyers, engineers and a bunch of other stuff to help it kept running.
Hi, Hack Clubber here. Fun fact: The 7% does not completely cover the cost of running a fiscal sponsorship program like HCB! That fee does not make HCB a net positive product to run in terms of cost. It just helps offset it a little.