Even if you aren't convinced by the potential spying threat from China through Huawei kit, there are other problems associated with their use as a vendor, namely their worrying habit of copying source code from rival manufacturers.
Quick example - Huawei used Cisco source code to implement EIGRP, a Cisco-only proprietary routing protocol in their kit - https://www.wsj.com/articles/SB10485560675556000
They only stopped selling kit with this functionality when Switchzilla sueballed them.
Assuming for sake of argument that they'd continued to sell it, and a flaw was uncovered in EIGRP that allowed for DoS or information to be leaked from a target device (like this - https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20051220-eigrp ), Cisco would patch their code and their devices, but you've got no guarantee that Huawei would have access to the fixed code, nor that they would fix it themselves, as they've obtained the code by copying the original source code (which I can only assume was leaked or obtained via questionable practices, and you can't guarantee that mechanism to grab the afffected code is still open to them).
If they have previous for copying code just to support a proprietary protocol used by a competitor, we have no guarantees that the rest of the code running on their devices isn't copied from elsewhere, and we have no assurances that they'd patch upstream fixes for vulnerabilities found by these rival vendors, or even that they've realised their own devices are at risk to an exploit affecting someone elses switch and associated source code.
I'd be less concerned if they were licensing code from other vendors and using it with commercial support in place, then they'd be tracking the versions properly, they'd entitled to see the fixed code and would apply it themselves.