I know it's cliche, but they're short and sweet. They are able to communicate the joke or the emotional arc that doesn't stretch the premise too thin to fill time. You can feel when a movie has run out of steam, and you check the run time and you think that they could've done with twenty or thirty fewer minutes.
I'm super stoked that one of Diisney+'s original programs is SparkShorts, where up and coming stories at Pixar can experiment and make their own shorts. And they were all cool. My favorite of the first four to be released was Kitbull. It's about the relationship between a stray kitten and a pitbull, and it has not dialogue, and was a great portrait of those two animals and how they reacted to each other.
It's not about quantity of content, but quality, and that's what these shorts are.
