Sonic:
The Internet is not a naturally occurring thing. It didn't spring out of the ground, it didn't fall from the sky, it wasn't created by random molecular adhesion, the was no "Big Bang" that created it. Not even the Great and Powerful AlGore could summon it from the ether by himself for the benefit of all mankind, no matter how hard he tried...
It was built: First by government agencies (and research facilities, schools doing government research ...) then commercial entities....including ISPs.
Where do you suppose all the connections come from? Who do the ISPs connect to?
Don't confuse the simplicity of home networking with the day-to-day management of the background infrastructure. "It's complicated." Trust me.
Beyond the actual nuts & bolts networking involved, there is a massive matrix of federal, state, and (possibly) local regulations that must be met. There are the contractual obligations to be met (home users and comercial SLAs). There are rules / regulations about how one provider can/must deal with other providers.
It's much more that just sharing some bandwidth you have laying around.
If you want to start gathering clues, start investigating the (relatively) simple infrastructure of the Telco (i.e., dialtone service).
Telephones are easy: all the wires in the country all end up at one (very secret) location, where they are twisted together and capped by the world's largest wire nuts. Really. Personally, I was shocked when they showed it to me.
I suppose the bottom line is that ISPs are required, carriers are required, infrastructure is required (and must be failrly shared). Being that the above are not naturally occurring, someone's got to do it.
And, regardless of how long the Great & Powerful AlGore stands on the mountaintop screaming at the heavens for devine network creation, he has yet to plug in his first backbone router and should be considered an unreliable source for Internet connectivity.
Good luck on your search for the Truth.
Scott