I also find the back gesture to be surprisingly convenient. It’s easier to reach, in part because you can reach it from anywhere on either side of the screen. And the gestures from the bottom lets you go back/forward an app, home and also all of the recent apps. And also assistant or an app of your choice by swiping from the bottom corners.
Plus, on top of that, on LineageOS you can also bind a custom action for a second stage for the back gesture if you swipe it further away, like kill app or go back to the previous app. And left/right side from the top for notifications/quick settings, and swipe at the top for brightness.
Zero pixels used for what, 9 different actions? It’s pretty sweet!