I don't disagree that Netflix could have / should have done better. But everybody screws these things up. Even broadcast TV screws these things up.
Live events are difficult.
I'll also add on, that the other things you've listed are generally multiple simultaneous events; when 100M people are watching the same thing at the same time, they all need a lot more bitrate at the same time when there's a smoke effect as Tyson is walking into the ring; so it gets mushy for everyone. IMHO, someone on the event production staff should have an eye for what effects won't compress well and try to steer away from those, but that might not be realistic.
I did get an audio dropout at that point that didn't self correct, which is definitely a should have done better.
I also had a couple of frames of block color content here and there in the penultimate bout. I've seen this kind of stuff on lots of hockey broadcasts (streams or ota), and I wish it wouldn't happen... I didn't notice anything like that in the main event though.
Experience would likely be worse if there were significant bandwidth constraints between Netflix and your player, of course. I'd love to see a report from Netflix about what they noticed / what they did to try to avoid those, but there's a lot outside Netflix's control there.