Actually, on the Pixel 6, the fingerprint scanner works fine, even with a glass screen protector.
The secret is to first turn on enhanced fingerprint sensitivity and only afterwards train your fingerprints.
As with all fingerprint sensors, it is critical to train using the ball of the finger, the base, the tip and both sides in different combinations and angles. You can get even better matching if you train the same finger twice, using two fingerprint slots.
While not as fast as the capacitive sensors of the past, properly configured and trained, the Pixel 6 fingerprint sensor works reasonably fast and reliably.
It just does not work 40 percent of the time. I have to press and press over and over again to access the phone. I had a Pixel 3a and other phones and never had any issues. I am returning the phone. Nice features but whats the point if you cannot access them. My son's Samsung never had these problems.