[Agentlien]

If you're making games targeting consoles there are usability requirements. Any loading screen which takes more than a few moments needs at least a spinner to indicate it's not stuck and if it may take more than a certain time (30s? 1 min?) you are specifically required to use a progress bar. But there's no requirement on how accurate it is.

While working on a popular AAA franchise at EA, we had loading screens which were sometimes really long and depended mainly on your connection speed. We estimated a worst case time for clients with slow Internet but not slow enough to time out and then made the progress bar driven by a timer from zero to this time.

Even knowing how it worked I repeatedly found myself intently staring at the loading bar.