Pixel 4 update lets Smooth Display kick in more often
You'll get more of the 90Hz smoothness you paid for.
Pixel 4 XL teardown reveals remarkably tiny Soli chip
The chip was so small iFixit had trouble finding it.
Google explains when it slows down the Pixel 4's Smooth Display
You won't experience the 90hz refresh rate all the time, and that's by design.