I faced this problem too. I am a Linux user personally, but use Windows at work. I am not a phone person, but do use it regularly.

I sync org files to phone (using Syncthing) and use Orgzly to access these from Android. Although it is possible to install Emacs in Android as a terminal tool in Termux or even as a GUI tool, you need to connect a keyboard to do something sensible. Long story short, if your phone is your daily driver, Emacs may not be for you as it is keyboard oriented. But if you are a computer person who occasionally uses the phone, there are ways to get by.