Here's one counter example: Progress indicators can be indeterminate, when the duration of the task is unknown but you still want to communicate to the user that something is happening.

You can make an indeterminate <progress> by not specifying a value attribute, and then styling it with the :indeterminate pseudoclass (TIL).

It's well worth it to read the Apple Human Interface Guidelines, even if you don't develop for Apple platforms, they have some good universal UI advice:

Progress indicators: https://developer.apple.com/design/human-interface-guideline...

Gauges: https://developer.apple.com/design/human-interface-guideline...