I moved from Pixel 3 yo Pixel 6. I bought the hype and loath this phone.
Finger print scanner is garbage.
Gesture navigation is garbage.
Drop calls
DND automatically turns on
Can't hear caller when answering calls with Bluetooth headphones
Very disappointed. ??????
FPS isn't garbage - it's better than the optical FPS I'd had on a Samsung. But coming from the capacitive rear design of the 3 (and the 3 XL, which I used), it is indeed slower and not quite as consistent. Capacitive FPS were pretty much infallible, but they're pretty much a thing of the past. Most other flagships are now using ultrasonic FPS, which are better than the Pixel's optical FPS, so you could consider them, but you'd be giving up a lot of the things about Pixels you probably enjoy.
Gesture navigation has been around for a while now - 2 years? - and is far, far better than when it was first introduced. Since that initial launch, and continuing today, there has been the option in settings to use the legacy 3-button navigation. It doesn't take long to get used to, and I, for one, find it more intuitive to navigate after having given it that time. But if you really don't like it, you can change it back to the 3 button configuration in settings.
I can't speak to dropped calls for you, but I'm getting the similar levels of network capture and better network speeds on the 6 Pro when compared to the S20 FE, with both having been better than the 3 XL. Any number of variables could impact this - with the cell provider and how they manage an existing call when the phone transitions between WiFi, 3G, 4G, and 5G sub-6/midband/mmWave networks during the connection being a likely culprit. And given you're coming from a Pixel 3 which lacked 5G, it might be further narrowed down to transitions between 5G network bands and 4G/WiFi. I Haven't had those issues myself (on T-Mobile, frequently transitioning between WiFi, 4G, 5G sub-6, and 5G midband).
DND can be configured to turn on/off automatically at given times, when driving, when gaming, etc - have you checked to make sure none of those settings are possibly the culprit?
Haven't had any issues on Bluetooth answering calls via two different headsets or in the car. Have you tried different Bluetooth devices?
I wouldn't expect the FPS to get noticeably better, so if that's a dealbreaker for you there are other options this year in which the FPS is a newer tech that will run smoother and more reliably. Gesture navigation should be a total non-issue, as you can just turn it off if you want.