I recognize the magnitude of the issue. But if the govt is able to crush Airbnb then people will begin looking for solutions elsewhere.

Given the problems with many online market places, the better idea is probably some sort of broader ebay like classifieds network which could include airbnb like listings.

Some sort of identity solution is a big piece of the puzzle (slashtags maybe) but what is REALLY needed is some sort of 2 party escrow which may not be possible over Lightning. Maybe built in (possibly hidden) Lightning to Liquid swaps & Liquid escrow contracts could be a fix. Once escrow is solved then bootstrapping becomes somewhat easier because people can sell & ship things with less risk & the network effect can grow.