YouTube, Twitch, Amazon Prime, Hulu, etc have all demonstrated to stream simultaneously to hundreds of millions live without any issues. This was Netflix's chance to do this and they have largely failed at this.
There are no excuses or juniors to blame this time. Quite the inexperience from the 'senior' engineers at Netflix not being able to handle the scale of live-streaming which they may lose contracts for this given the downtime across the world over this high impact event.
Very embarrassing for a multi-billion dollar publicly traded company.