The iPhone 12 notch is less than 2mm taller than the newly-thin bezels on the MacBooks, and the iPhone takes 1080p video as well and has even MORE sensors packed into that space. I totally understand the argument for increased screen real estate, but isn't there a point of diminishing returns? At just 1.8mm of vertical space it's barely handful of pixels at that point. If I'm going to give up part of my screen, i'd rather it be a thin strip of pixels across the top rather than a sizable chunk taken from the middle.
It will certainly be intrusive to apps that have enough menu items to reach the middle of the display. And that's not even taking into account how visually intrusive it will be, at least to some users. Plus, it doesn't really "give you back" any space because in fullscreen apps, that area is still inaccessible.
There is no reason to justify the notch in my opinion. I believe that Apple introduced the notch because marketing is more important than the user experience to them. They wanted to add the MacBook Pro to their family of iconic notched devices.