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.
I was constantly backing out of my app when all I wanted to do was turn a page. Therefore I went back to the three buttons. The gestures are nifty, but I was always running into problems with the gesture happening when I didn’t want it to.
My tech averse spouse finally wanted a smartphone and I knew he would not understand gestures as he is very literal. So there was a double bonus: the buttons are a lot better for him.