The Android Wear app is necessary for handling all the interaction between the watch and phone. it looks like the Huawei app is just for collecting and presenting some of your fitness data. If you don't like the Huawei one, don't use it. By design as an OS, Android Wear allows any fitness app...
I mostly uses it when there's an address on screen (like in a text, email, etc.) that doesn't automatically link. I pop up Google, it scans the screen, sees the address, and gives me a maps link. Very handy. It's also useful for movies and people.