Its just how long you are meant to let the coffee brew. Try if you make tea you need to let bag steep for a minute or 2. But actually timing it???? Useful if you are a goldfish may be but otherwise i dont understand who can’t remember to do something in 30 seconds.
Fwiw i oftrn let me aeropress brew for a few minutes. 30 secs is hella short.
That’s indeed quite short for a brew time. 30s is your typical plunging time
30 seconds works fine for other semi-pressurized brewing methods like turboshots or soup.