mar, just because Kieran doesn't talk about everything he does behind the scenes to get a grip on this doesn't mean he isn't. He's dedicated a lot of time (and money) to this issue over the last two weeks.
Also, unfortunately zap.stream (in itself), in it's current form, is a single point of failure challenge on a decentralised protocol. This is why Kieran has put a lot of work into the new zap.stream core as it exists right now. We need to decentralise everything on and around the nostr protocol and live events are no exception. However, bear in mind that the current (new) core literally just entered production. There is more to come.
Think of it as an Alby-Hub alike platform that can be deployed by anyone who has the means to run it creating a network of hosts for nostr live events. Anyone who provides an endpoint can get paid for the bandwidth usage if a creator uses their endpoint. Creators would have a vaster selection of stream serves (including in their region) and the resources required to attack such a network of endpoints gradually explode.
TLDR - we're still early