Internet is a set of routers around the world that forwards the packages to target destinations.
Imagine a situation where some actors try to send a massive amount of data per second, and they are doing this worldwide.<p>Could it slow down the internet because the main routers would be busy with forwarding DDOS packages?
You say "anyone", then "some actors"...obviously "A list" national governments have vastly greater resources available than some "because I can" PFY in him mum's basement.<p>Similar - "the whole internet". These days, large parts of that are semi-isolated ( <a href="https://en.wikipedia.org/wiki/Great_Firewall" rel="nofollow">https://en.wikipedia.org/wiki/Great_Firewall</a> ) in various ways. I would not bet on anyone being able include all of those parts in any DDoS.<p>I'd assume that any serious-about-cyberintel goverment <i>could</i> DDoS all the non-isolated parts of the internet...at least for at least a short while. If they really cared to.<p>But actors in that league do <i>not</i> play "because I can" games. What objective might such a government have, which could not be better achieved in other ways?