They don’t push any limits. They just make fun gadget that works by connecting a Pi or Arduino to some servo, and possibly connect a joystick to it. This is fine for any beginning engineer of course. But they never push any limits. The glitter bomb you mentioned is very similar. A decent engineer can make that in a single day.
Anything created by them can be made by a university student, often a first year one if they have prior engineering experience during their youth.
The other guys are desiging custom hardware, custom electronics, write custom firmware. It’s a lot more than a single input > output www.youtube.com/watch?v=XPXN0QejqM0