The way to deal with this is to constantly do live events, and actually build organizational muscle. Not these massive one off events in an area the tech team has no experience in.
They've been doing live events since 2023. But it's hard to be prepared for something that's never been done by anyone before — a superbowl scale event, entirely viewed over the internet. The superbowl gets to offload to cable and over the air. Interestingly, I didn't have any problems with my stream. So it sounds like the bandwidth problems might be localized, perhaps by data center or ISP.
Maybe they considered this event as a rehearsal for the upcoming NFL streams which I am guessing might have a wider audience