Ok, so I read more of the thread and it's a timing issue in terms of releasing updates via various builds. I still want someone to explain why we have a Beta process in the first place. The whole point of Beta is to test the IOS program for bugs, provide feedback, and start working on app updates while the beta process is in motion. Apple even says don't download this on your main phone because it might do damage to the main phone. Basically, from the day WWDC happened to now, developers had some sort of program for the new IOS update. I would think it's like writing a semester long paper for school. You get the assignment on day one, the teachers tells you when it's due, and unless you procrastinate, you are working on that paper the entire semester and the good students would try to get it done early so they don't need to worry about rushing it with a day or two left.
Betas are useful, but they're not problem free. Simple apps can usually sail through the betas, update a few things, and be fine come release day, more complex apps cannot. Also newer betas can break things just as much as older betas.
To use your analogy, imagine you start the paper you mentioned, every two weeks your professor makes changes to what they want you to include in your paper. Some changes are little (like font size), other changes, not so much (like switching between citation formats, or even if they wanted a table of contents or not). You try and keep on top of these changes while you're working through your paper but they don't stop, every two weeks there's more changes.
In the past, this wasn't a huge deal because you would usually get a "freeze" date where the professor would give you their final round of changes and you had about 5 - 10 days to make sure your paper followed all those changes required before submitting it on the cut off date.
This year however is different, without warning the professor said "Here's the final round of changes, it's due tomorrow."
You basically have to stay up all night, making sure your paper has all those changes.
Software is much more complicated than a paper however. There are teams of people that coordinate a software releases and if someones app was broken during some of the later betas they not only have to find the bugs and fix them, but also do full regression testing to make sure those fixes didn't break something else.
Complicating matters is the fact that you can't submit an app to Apple without the GM seed, so if iOS 14 breaks someones app, they couldn't issue an update until yesterday at the earliest, and the approval process isn't instant, so someones app could be broken for iOS 14 early adopters and get trashed in the App Store by reviewers all because their fix is waiting in line to be approved by Apple.
In the past Apple sent out notices two weeks in advance to get your apps ready for submission. Everyone was expecting that and it didn't happen.