IPFS isn't heavy. Neither is neutrino, and afaik it already runs the back end of at least a couple of wallet apps. Something about bananas? LND and Neutrino together.

If mobile devices weren't encumbered by proprietary firmwares and gated by app stores I'm sure that p2p apps on them would proliferate. Mesh networking standards are everywhere too, they just are hardly in use because someone doesn't want you to get off the grid where they are surveilling you and selling your dossier to the highest bidder.