The Pixels had the worst option for a while: the under-screen optical sensor. Slow and prone to failure. They've since switched it out for an ultrasonic sensor, but it was shockingly bad for a few years.
I had an Pixel 9 Pro with the ultrasonic sensor and I found that it wouldn't work at all with a tempered glass screen protector. The optical sensor they had for previous generation sort of works fine with a screen protector
Ultrasonic ftw.