How big are your hands? Do you have a special technique? I've got the one-hand keyboard setting enabled and I still can't type with one hand. My hands aren't big enough to hold it between my palm and finger tips with any sort of stability while using my thumb. It works better if I stretch out my pinky and rest the phone on top of it (not even touching the palm so the thumb has more reach and mobility), but it still falls a lot like that so I end up always reverting to two-hand use. And that's just for typing, I can't do light browsing or anything else with one hand like I did on the Nexus 5

To give a hand size comparison, the length from the very bottom of my palm to the top of my index finger is nearly equal to the height of the pixel 3. My index finger is maybe .25" longer. I'm an average height adult woman (5'5”), with hands proportional to that. I can play a standard size guitar just fine (ok, some bar chords are hard), but I haven't been able to buy an ergonomically comfortable flagship Android device in years now.