It isn’t, but at the same time, smart hackers were working with highly constrained PC hardware in the 1980s and early 1990s and were cranking surprisingly good performance out of it. Folklore.org has plenty of stories about it, and John Carmack’s early career history is very impressive. We mustn’t forget the demo scene hackers either.

That's why phones and windows use animations. You can also use intersitials related to the product you sell. Users are usually fine seeing many changes on the screen quickly because it gives the impression that stuff is happening on the background. For example in the interstitial, use an animation that takes up a small portion of the screen and not just a simple spinner or loading icon. Something more complicated with 2 or more things moving or changing at once.