Fifth time a charm
Generally, my macOS updates happen on their own consistently. Recently over the last year or so the updates went away from incremental to full updates with gigabytes of downloads replacing my previous version in full. It seems Apple was using this to sign certificates more accurately. This was an annoyance but in these days of unlimited internet which runs at around 2 TBits a month, it has become irrelevant.
However, over the last week, my work Macbook was attempting to update to 12.2.1 to no avail. This was an emergency fix by Apple to fix some zero-day bugs, so I thought I should install this ASAP. It usually takes a couple of hours to download and install, so I start the process end-of-day before I leave my work desk. The next 3 mornings the same thing happened. The update had tried to be installed and failed. Error reporting to Apple kicked it but could not progress after that.
Then, I wondered what it could be. I usually work with my notebook closed since I use two large-screen monitors each connected to Displayport over USB. So I presumed that perhaps that the lid closed was causing some challenges - so the fourth time I tried leaving the Macbook with the lid open. Perhaps this might solve it. And it did not. A fourth nightly failure happened.
The next step was to reduce the complexity of it all. I closed all the apps and rebooted the system to not open them again on login. I disconnected all the peripherals - the mouse, keyboard, webcam, my new addition the Logitech Litra Glow light (highly recommended), and my two monitors (connected over USB-C). And another fresh restart brought it as close to a fresh system (without a full software reinstall) as possible.
And the fifth time was a charm. Everything worked fine. 12.2.1 was in and this chasm was finally crossed. The experience felt like learning about Genghis Khan invading India in the twelfth century seven times before he made it successfully to capture Delhi. Brought back memories of learning it in history class growing up. The moral of this is to simplify and try again at the barest of basics - eliminating as much complexity as possible to make progress. That was the meta-learning. If one is looking to learn from everything one does. The answers are everywhere.