Isn't that what multicast is for?
Multicast doesn't work on the Internet.
You might have a look at Librecast [0] which is a R&D project funded by Horizons Europe NGI0 programme via NLnet, aiming to the bring multicast to the current unicast internet and smoothen the transition of projects that adopt it. A great intro to multicast and Librecast is given in Brett Sheffield's 2020 LinuxConfAU talk "Privacy and Decentralization with Multicast" that is available on Peertube [1].
> To enable multicast on the unicast Internet we start by building an encrypted overlay network using point-to-point links between participating nodes. Once established, our overlay network can run whatever protocols we require, unimpeded by routers and middleboxes and which is resistant to interception, interference and netblocks.
The protocol seems like an excellent idea, but #3365a3 on black for the website text is one of the worst designs for open-source project websites I've seen yet.
Off-topic but I'm impressed with how many potentially revolutionary projects get funding from NLNet.
Mbone was fake multicast (today you'd be better off using a CDN) and I don't know if it's still operating.
I had a teacher in uni who was fairly convinced that some kind of intelligent multicast was the solution here.
But after working in ISP for a while I realised that the issue is getting ISP's to use cool protocols is just impossible and everything must be built at higher levels.
i guess but im thinking like multicast with the people sharing like bittorrent, just live. so you'd need to factor in people leaving and people leeching
So a multicast like derivative that is peer aware and can redistribute locally any available parts - which would require some sort of caching, which would probably break copyright etc... So perhaps that's the reason why nothing exists. \o/