I own the Hero 8. Hypersmooth is fine for tight spaces. The Grip for example is less than pleasant to mount on a bike or helmet.
A completely waterpoof camera with stabilization for mounting to my Kayak, for snorkeling or diving, is great too.
I like that I can film in 4k 30FPS and have "linear view" enabled. If the Hero 7 Camera could have done this...I would have just upgraded to the 7.
I like that I can carry less gear... and less weight. The Grip along with the El Grande Extension Pole was a bit heavy!
The Hero 8 doesn't automatically adjust for horizon tilt. If it is a static shot... correction in post isn't too difficult...but correcting panning shots...or getting them right can be a chore.
The Hero 8 just can't do "Jib" or "crane" shots. You really need a Gimbal to keep the horizon stable and the camera pointed in the right direction. My work around has been to use my Insta 360 One X, and selfie stick due to the size and weight...but the video quality leaves much to be desired.
While hypersmooth is great...and certainly has it's place, it doesn't completely replace the Grip.