Man who built ISP instead of paying Comcast $50K expands to hundreds of homes

I'm going to put my hand up and say I have absolutely no idea how an ISP works. He runs cables to each house in the area... now where does the other end go?

Not sure if it’s what the person in question did, but there’s a whole guide that pops up on here occasionally regarding building a wireless ISP.

https://startyourownisp.com/

I can't find any section of that guide that talks about peering or whatever ISPs are supposed to do to connect to the broader internet. Do you see any step that explains this?

It's the 2nd step

https://startyourownisp.com/posts/fiber-provider/

If you just Google then it's usually called leased or dedicated internet

Just some (US) examples

https://www.business.att.com/products/att-dedicated-internet...

https://business.comcast.com/learn/internet/dedicated-intern...

https://www.verizon.com/business/products/internet/internet-...

So they're leasing ("buying"?) fiber from the same ISPs they're trying to displace and relying on that payment to provide them with continued internet access? This doesn't sound like a real first-class ISP, but something akin to an MVNO where they're at the mercy of the same companies they're competing with. I get the initial sale might seem fine, and the established ISPs might be fine with this as long as the company is small, but why wouldn't these companies shut them off (or raise the prices, etc.) when they grow too big to become dangerous?