At this point, Federighi's explaining the great advantages that will mainly benefit
common users developers. So... that gives me time to tell you that going forward, think of Macs working more like how iPhones and iPads do. Essentially, Apple's made its entire ecosystem more like its own, so that all services work better on their desktops than any kind of stability and smoothness than most Windows machines could achieve yet. Given Apple's command on the technology world, you can certainly hope extensive developer support backing up the move. That's one of the biggest advantages of being a company as big as Apple – you make a move, and the software world will work for you to justify the hardware moves.
He's showing how even with all the system animations, all app launches are instantaneous. This is part of Apple's reason for shifting to its own processors, and vertical integration plus better optimisation of the full software stack and the hardware optimisation is what Apple has always excelled at.
The Apple M1 is based on the 5nm processor, and uses Apple's unified memory architecture. What does that mean? Apple's basically thrown in a lot of features right into one combined unit, which can do a lot of things together at the same time. In fact, Johny Srouji of Apple says that its high performance cores are the "world's fastest CPU cores".