-First: No PWM flickering. Check this thread if you've never heard of it.
https://www.reddit.com/r/apple/comments/7uv6m3/iphone_x_uses_pulse_width_modulation_which_is_a/
This flickering was definitely annoying to me, and causes eye strain
-Next: Better viewing angles. LCDs have way better viewing angles with no blue shift like the X suffers from
-No chance of burn in. OLEDs can suffer from burn in.
-Generally cooler color temps. Some, like me, love that
-Longer lifespan. OLEDs have shorter usable life
-No PenTile. The XR has ALL the sub pixels
The only advantage to OLED i've seen is slightly better black levels. Who cares.