It completely depends on the specific video file. HEVC and AV1 are more efficient in general, but most of their benefits become apparent with 4K video, which they were specifically designed to be better at handling than AVC. It also depends on your phone’s software and hardware, as it might not be fast enough to encode in real-time with higher compression settings (and you don’t get to use things like 2-pass encoding which can drastically lower bitrate without sacrificing visual quality).