I love that you had such an annoying update experience that you went ahead and created 2 memes about it and postet into a total of 4 communities, only to vent your frustration. Keep going, this is great!
Is it actually measuring progress of anything as it's happening, or do they just update the percentage when it passes certain milestones? So many progress bars are just straight-up lies that slowly increment a number until the real process finishes and it shoots to 100% from wherever it was at before.
They do not generally reflect time passed but amount of task done.
For example, let's say you have 100 files to configure as part of an update or installation. 99 of them are really small files that fly by, but the last one is a few gigabytes of data that needs to be configured. The bar might hang on that one really large file, then fly by the rest of the process as these files are very small and go quickly.
In this case the progress bar should show the percentage of processed data, but just using the amount of tasks or number of files is quicker and most often than not works fine