One thought about this section:

> To give you an example, a faster-spinning spinner makes the app seem to load faster, even though the load time is the same. This improves perceived performance.

Perhaps due to poor design by companies that abuse the fast loading spinner when, in fact, nothing is happening, I instinctively trusted the slower spinner more.

The only thing that I trust is loading bars that make nonlinear progress, clearly indicating that there's specific steps and/or measurable progress happening.

my first instinct was "the slow one is struggling so it must be doing some heavy work"