There’s not really too much of a debate, just a lack of deep understanding of how the infrastructure works under the hood.

The other person (rightly) doesn’t want to share their local network (what’s behind your wifi router) with their neighbors. My only point was that, much like current ISPs, you don’t share any networking with your neighbors. The only thing remotely close to ‘shared’ would be the individual uplinks (your ISP connection) from each residence to the networking gear of the ISP.

A local ISP and a Telco aren’t (shouldn’t) going to be handling the base networking layer any differently. They’ll all have individual connections between them and subscribers, and the only way that I could get into your network is to setup services and configure either side to talk to the service on the other.

To actually ELI5 (which I am exceptionally bad at with actual 5yos), Alice and Bob both get their toys from Charles (Telco ISP) who charges a lot of money, and doesn’t treat them well when they try to use the toys they got. Dan comes a long and works with Ed and Fred to set up a local toy store and try to treat customers better. Bob (irmadlad) is concerned that the new local toy store means he’ll have to share the toys he bought with Alice, not realizing neither store makes you share your toys.