I keep reading that OLEDs are more efficient but when you look at the final products, OLEDs (even with elaborate heatsinks) are dimmer than LED-backlit LCDs. There's definitely a lack of solid facts on this topic.
OLED displays are typically less efficient than a good LCD. Anyone who claims they are is perpetuating a myth likely rooted in the fact that OLED power scales with APL. They forget the high base cost of keeping the active matrix powered.
It took a while for OLED mobile displays to achieve the brightest we had with high end LCD mobile displays for years. There are still mobile LCDs just as bright as any OLED available (iPad Pro 12.9).