Ever since its appearance in Android Pie, I always consider 2 button navigation is a bad attempt by Google trying to play catch-up with the fad generated by the iPhone X. However, due to a bug with A13 QPR2 it had to be temporarily removed and many were not happy about this. So, 2 button navigation users, may I ask why do you prefer this method? To me it makes you do more for the same action whilst doesn’t save any screen space.
I will be honest, it’s been three phones since I had one that even still showed the option.
It’s all either the full 3-button nav, or the proper gesture navigation. 2-button was this hybrid Google did very briefly, but luckily it’s gone now.