Provide a link to evidence of the hardware back door on a consumer laptop or a Cisco router or something. Something that turns out to be in all of such a device.
The US doesn't have a backdoor into iPhones (as an easy example) as evidenced by the FBI not being able to get into the iPhone of that San Bernadino shooter and almost resorting to paying an Israeli company for their highly controlled exploit (that used a now-outdated zero day) before they figured out a way in via brute forcing the PIN without resetting the device. Which Apple fixed.
Provide example of the backdoors you're referring to and don't just link "omg china hacked something!!!" The OPM hack in 2014 came about because the US contracted an Indian company to manage that data (lol) and the Indians didn't secure it properly. If China had backdoors then quite literally nothing would stop them and if they were hardware backdoors, as you say, then there would be no trace in the logs generated by the operating systems, making China practically unstoppable and the entirety of the USA compromised, along with pretty much the rest of the world and no one talks about this apparently but you.