All US phones have components manufactured in China as well as all over the world. It is not a stretch to think the foreign governments couldn't get in the middle and create vulnerabilities or straight up drop attacks on different components they have access to. How is Huawei any different?
Are we supposed to take their complaints seriously when Snowden leaks revealed the NSA hacked Huawei servers to find vulnerabilities they themselves could use to spy on people around the world. /shrug operations Shotgiant doesn't matter? If the NSA hack revealed that Huawei was injecting spyware it's time to release the details of how they found out.