That sounds like an impossible solution to reach mass market. Simply because regular internet for most people is just the internet company comes and connects it to their computer.
I don't know, I definitely overly simplified the task but
https://en.wikipedia.org/wiki/Guifi.neta spanish mesh network was born in 2004 due to lack of service from said ISPs and in 2018 this network continues to grow to this day - "over 46,000 km of wireless links" that seems pretty large scale.
110 new nodes last week
https://guifi.net/enIt's still very niche. By mass market I mean your everyday teenage girl (who are not into technology), average FB user, mom and dad, grand parents. Just basically the vast majority of people. Anything that requires an extra step is a bid no no.