I guess this has been said before but I want to reiterate it here.
The 3 button navigation is simpler, much faster than gestures and less prone to input errors than gessure navigation.
It’s easier to use the phone one handed when using 3 buttons especially considering the size of phones nowadays.
The only real downside to the 3 button bar is the space it takes away from the screen. I can’t deny you get better immersion due increased screen size and gestures being intuitive (for me at least.
With that said I understand that depending on the brand the feel of gestures and their quality can vary (like between a pixel phone and a xiaomi device), but in terms of efficiency (and maybe slightly improved battery life due to less animations) and simplicity the 3 button navigation is still miles ahead.
Swiping from anywhere on the edge of the screen is faster because your thumb is already there. Having to move all the way down to the bottom of of the screen with your thumb takes longer. Also take into account the chance of missing the button and having to try again, vs a gesture that needs to be much less precise