Off axis viewing being "horrible" is not a sentiment echoed by many, it's just an opinion of a minority.
ZERO credible display professionals weigh any of these cons in favor of LCD to win overall.
PWM is certainly an issue for some...but I believe it's about 10%, though we don't even know the real numbers.
I'm not sure what this obsession is with off axis viewing, anyway. Take the XR off axis viewing into account:
"The iPhone XR LCD definitely shifts a little pink and drops brightness quickly when you look at it off-axis, which often leads to a bit of a shimmery effect when you move the phone around".
https://www.theverge.com/2018/10/23/18011306/apple-iphone-xr-review-camera-screen-battery-price
The only time I see a slight color temperature shift on the XS Max, is if I move the phone around with the settings open and I'm moving the phone around. Flat on the table and in hand where I hold the phone stable, it's identical.
You either get screen dimming (XR), or a slight temperature shift (X/XS/XS Max).
As for your "little tangible benefit", why is it used in nearly all flagships of Android phones? Especially where Companies are fighting tooth and nail to compete with the best features, they certainly all use OLED.