With Apple allegedly prioritizing battery life and 5G on the iPhone 12, iPhones might only get 120 Hz displays next year
According to tipster @jon_prosser, the reason the iPhone 12 lineup won't be getting 120 Hz displays is "100 percent" down to battery life concerns. The upcoming iPhones will be the first to support 5G. As we've already seen in the Android space, 5G radios need much more power than 4G, resulting in relatively lackluster flagship battery life.
120 Hz displays are battery-intensive as well, so Apple likely had to compromise between 5G and a high refresh rate to ensure that iPhone users will get a full day's charge out of their phones. The battery life question is particularly relevant this generation. With the iPhone 12 lineup, Apple substantially increased battery capacity. iPhone 11 Pro Max users can easily get 1-2 days of use on a single charge.
With the iPhone 12 lineup sporting 5G antennas, it'll be a challenge for Apple to ensure that battery life and screen-on time don't regress this generation. We'll likely have to wait until 2022 for 5G radios and display tech to become power-efficient enough that Apple can incorporate both in the iPhone's form factor without giving up on battery life.