You're grossly oversimplifying the complexity involved with "streaming" a video. Specifically in the context of a service like Disney+ or Netflix. Additionally how do you "find" that content near you? How do you ensure it is available? How do you ensure it is correct? Who owns it? How do you ensure copyright/drm/licenses are respected? What do you do when it disappears? The gains are incredibly slim, if at all, for the engineering challenges it introduces.
You also confuse "CDN somewhere" with OpenConnect box literally inside your ISP's DC. It is probably faster to get it this way than it would be to P2P it from your neighbor since, at the end of the day, that P2P traffic _must_ go through your ISP and their ISP. It will not, by definition, peer at the local hub. You are _NOT_ on a local network with your building/neighbors/etc. Your communication routes to your ISP and then out to anywhere else, even if that somewhere else is on the other side of your wall.
Even if it was possible. Even if it was slightly faster. Do you really think studio execs are going to be okay with customers hosting/serving their content off their machines? Even _IF_ this was "technically" a good idea, this is a non-starter from the business standpoint.