used to alert the rider that the software has overridden user input
I think this is the whole point. Riders were asking more of the boards than the boards could do, and when the board was unable to comply the rider would lose their balance. Haptic feedback tells the rider "nah, not doing that" so they're aware the board isn't going to do the thing and can adjust their balance accordingly.
My dad (silent generation): Back in my day, a guy could get a job at a gas station and be able to own a house and support a stay-at-home wife and kids. I dunno how you kids make it.
Me (gen X): Back in my day, a guy could get a job at a gas station and afford rent and food. I dunno how you kids make it.
I'm not sure when the guy in the comic was born. Medieval times maybe? Because economic conditions for working class folks have been getting steadily worse for the entire lifespan of everyone alive today, at least in the US.
It was probably closer to $30, but a squeezy poop claw to clean up after my dog. Works so much better than a shovel.