Huawei uses a massive 1/1.54" sensor on its ultra-wide-angle shooters, but has been unable to pair it with a lens that can provide an industry-competitive field of view. Things are expected to change with the upcoming Mate 40 Pro, however, as a new leak claims the phone will sport a new, innovative lens type.
https://www.notebookcheck.net/Huawei-Mate-40-Pro-touted-to-feature-a-freeform-lens-for-improved-ultra-wide-angle-camera-performance.463052.0.html