People are currently reading this guide.

Android 9 Pie has been functioning properly since it was launched. The only painful universal system that has been launched is a multitasking system, which is a strange combination of movements and buttons that don't function properly. Today at Google I / O, Google tells us that Google is building a new movement navigation system for Android 10 Q that removes buttons and allows scanning functions on both sides of the phone to act as backspace buttons. It combines the basic interaction of sliding the iPhone with Huawei's EMUI movement.
We looked at some of the latest Huawei and Honor phones, two brands running EMUI through Android 9, and found that the scanning side was once again a very good solution. I'm used to this when considering the incredible P30 Pro. I found myself repeating movements on Pixel and OnePlus devices that did not recognize it. The very good thing about sliding on both sides is pressing the button from the fixed position on the phone. The entire height of the two edges of the cellphone is scanned. No matter how you hold the device, the back rub is always there and does not require you to readjust your grip.
The disadvantage of Huawei's approach, which Google now imitates, is that it touches the application's sidebar, which is dragged from the left edge. Applications that work in this way include Gmail, Google Photos, Google Maps (actually it's the design paradigm of all Google-owned applications) and many other important and popular applications. In the case of Huawei, the disambiguation between friction is intended to present the menu and what should be a reverse action especially to alleviate menu friction and make the return more decisive. This is definitely not ideal.
Google's solution, at least until you have time to review your own application and encourage developers to follow it in your design guidelines, is to treat the first friction on the left as a menu trigger rather than backwards. So, if you want to sweep to the left to return, you have to do it twice. App developers seem to have the freedom to replace this behavior, but Google's voice is committed to ensuring that all Android device manufacturers and application developers adhere to the new navigation paradigm. Google will need time to release the two edges of the Android device to avoid friction, but Android Q launches us on this path.