Insane as in it works but the movement in the video is not anything like the instant pro gamer Elon made it out to be. It's amazing but it's diminished by over promising again. sic
I also think it's insane having Elon's m̶o̶n̶k̶e̶y̶s̶ surgeons poking at your brain, but maybe that's just me.
The exponential growth is that you see nothing for long time, until it is too late.
Once you blinked you will find the HN site is full of articles about the minimal-invasive brain microsurgery startups getting funded billions of dollars. And that we are in the midst of another tech bubble.
I'm not ready to declare exponential growth in anything but hype levels, yet; I don't see any great leaps forward concerning the fundamental problems faced by the field.
I think Neuralink is going to be more like SpaceX, not like Bitcoin.