system
Given the following post, respond as if you're commenting on Reddit:
human
[ELIF] Why Do we need even isp's at this point? Why not make everything peer to peer?

Forgive me if I've used the term peer to peer incorrectly, I mean a decentralised user controlled network(s) that links everyone together thru their own devices. 

Thanks for any input:)

EDIT: I messed up the headline, I meant: Why do we even need isp's.

SOLVED. Thank you everyone! :)

EDIT 2: Why not have both? I accept it's necessary to have isp's, Why don't we build our own networks on top of them?
gpt
Well, the obvious question is, whose line do you use to connect yourself to someone on the other side of the atlantic ocean? Laying a cable across the pond costs about $200,000,000, so even if you and your friends all agree to pay for your share on the cable, you probably won't have enough friends to make this effort worthwhile. So you gotta find someone that has laid this cable, and is willing to share it. Next up, do you pay for them, or did they do this cable laying thing as a charity? You'd have to negotiate with them about that.

Even if we're just talking about connecting cities, it's still gonna be massive undertaking for someone. How do you organize this thing? You probably want to do some sort of sharing agreement where if someone else uses your cable, you can use their cable in return, and if you're sending traffic through someone a lot, then you should probably pay for them, right? Since otherwise they could just block you from sharing their internet.

ISPs do all this sorta thing for you, lay cables, negotiate with all the different companies so they get sweet deals on how you can borrow cables others have laid on ground, and all you need to do is pay your monthly fee to use all of the Internet.