Are the margins thin and production slow so that multiple suppliers are needed? If someone does not trust a supplier why it is hard to just keep them out completely? Is it more about politics beyond the network rollout?
Personally, I'm worried (not sure that's the right word) that China will just do it's own thing in the near future. It was a miracle that LTE phones work worldwide, IMO. China had/has its own 3G CDMA tech. I wouldn't be surprised if the market gets fragmented in later releases of 5G or with 6G.
So they were allowed to join the WTO, and Qualcomm made billions in IP royalties.
I don’t have the evidence at hand. Perhaps someone else can find it.
In true British fashion we'll end up with a compromise that upsets everyone.
If a major Chinese supplier is completely excluded because they are Chinese then it will be seen as a very deliberate snub. This in turn will make it harder to achieve the goals mentioned above (investment, trade, etc). Instead, this kind of compromise is so the Chinese government don't lose face and Britain can still meet the national security requirements defined by the United States.