Am I crazy if for something like an online purchase, I kind of expect it to take a second or two to process the payment, so I would assume something went wrong if it was 200ms?
IIRC TurboTax has a bunch of loaders / spinners like this, similar idea.
Your comment reminded me of when Google introduced "Instant Search" in 2010. Here's an old HN thread from the launch: https://news.ycombinator.com/item?id=1672391
I’ve definitely had in the UX side a situation where the PM/Owner types asked me to introduce a delay in the “disabled button with loading spinner” such that the user sees it for a visible amount of time because our API was too fast for their taste.