Is called present progressive, which is a useful tense with a useful grammatical aspect, just as Arial is a useful font. Neither of them belong in a screenplay.
It’s a natural way to describe what you see in your head. “She’s sitting over there, he’s making coffee, the dog is chewing a sex toy.” However, readers had present progressive beaten out of them in screenwriting classes. It reads like bad grammar in a script because it’s taught as bad grammar.
Use simple present tense. It’s mindful. It’s direct. It’s compact. It’s a guardrail against novel-like prose in your description paragraphs. Also, because that’s the convention, it appears professional.
He digs a hole. They run for their lives. She sells seashells.
