That is because they do inject a delay.
https://apple.stackexchange.com/questions/17929/how-can-i-di...
https://superuser.com/questions/455313/disable-os-x-enter-fu...
It looks "pretty" to the UI people.
https://apple.stackexchange.com/questions/17929/how-can-i-di...
https://superuser.com/questions/455313/disable-os-x-enter-fu...
It looks "pretty" to the UI people.
https://thedailywtf.com/articles/The-Speedup-Loop
tl;dr : programmer inserts a large empty loop in a UI, so that in weeks when he achieves nothing, he removes a single zero from the end of the loop counter to speed up things a bit.
We later created a light version for a specific use case, and the product owner came prepared with a nice splash screen for this one too. The app was so lightweight that it loaded near instantaneously - so the engineer added a six second delay just to meet the splash screen requirement.
Buys them time to get stuff done under the hood while you are gazing upon the 'sands of time' (good old Windows hourglass).
It conditions you/me/everyone to be impatient. I opt out of all such transition effects on my phone. I prefer that the screen goes black of freezes until the next screen comes up. This way I don't get distracted by irrelevant junk (spinning wheels, hourglasses, etc.). It is crunching bits. Don't add more junk to it. Let it crunch bits without tricking me.