1. The Chinese National Intelligence Law requiring every citizen to "intelligence work".
2. Huawei had the potential to reach mass adoption outside of China.
3. Huawei is a company deeply connected to the PLA.
4. Therefore Huawei, not only is its HQ required to spy for China, but that it is very likely to work with the PLA to spy for China.
[1]. https://en.wikipedia.org/wiki/National_Intelligence_Law
[2]. https://www.cnbc.com/2019/07/08/huawei-staff-and-chinese-mil...