Making music. The iPad is much better for performing than a computer. There is a huge range of instruments, effects, sequencers, etc. available on the iPad. Things like physical modeling and chained reverb can eat up processor cycles so more performance is always welcomed.

Both Final Cut Pro and Davinci resolve can also use as much power as you can give them though it isn’t clear to me why you’d use an iPad instead of a Mac. They also announced a crazy multicam app for iPads and iPhones that allows remote control of a bunch of iPhones at the same time.