Tipster @jon_prosser claimed that Apple's alleged decision to skip on a 120 Hz iPhone 12 display was "100 percent" because of battery life concerns, with the 5G radio taking priority. This might mean that 120 Hz displays will only make their way to iPhone in 2022.
https://www.notebookcheck.net/With-Apple-allegedly-prioritizing-battery-life-and-5G-on-the-iPhone-12-iPhones-might-only-get-120-Hz-displays-next-year.497757.0.html