If it is a phone with 6 inch 2k or 4k screen. Then probably you are right, you don't need AA.(Honestly I don't know if my phone have aa enabled or not, because I can't really see the pixel with bare eye) But for 27 inch 4k screen, it is still not enough.
BTW. It's really obvious for a CJK user when the AA went wrong for whatever reason. Take an example, this issue: https://github.com/marticliment/ElevenClock/issues/241