I doubt if this blockchain based Handshake domains concept would ever gain traction with established businesses. People are undermining the need for central authority in favor of proprietary extensions which are only going to fragment the name resolver landscape. It would all boil down to how the big techs respond to this bubble. Unless companies like Cloudflare, Google, Amazon recognize those name resolvers these communities would be severely restricted to niche set of users like the deep web.
These TLDs might just end up being as obscure as .onion address which at least does not suffer from name resolver fragmentation. Just my 2 cents.