Back when I was 16 and the Dial-up was slowly dying, I took a cable connection and start selling internet to my neighbours.

By the 3rd year the network reached 3 blocks around the neighbourhood and I had ~50 paying clients. I still remember I did that with an old Intel 486 running Slackware Linux and a bunch of ipchains MASQ scripts. I had even a small local website where you were able to see your traffic ( I remember I was paid 10EUR/500MB or something. )

Back then I was not alone. Almost every neighbourhood had those networks, but at one point they started to unite together and the bigger ones were buying the small ones.

Now the biggest problem would be regulation, rather than the hardware requirements.