In the past we had Napster, Gnutella, eDonkey and BitTorrent. They did this for free, which is probably a bit less illegal than what you are proposing, but IANAL.
For all the noobs that can't handle "complicated" file-sharing, there's Cuevana and the likes. Sure, you could bolt streaming sats over LN on top of it, but these are centralized services and are being attacked and taken down regularly... Do you really want to enter that world?