The issue with 5G is that there is a lot more software involved e.g. software defined networking, network function virtualization, edge computing, containerisation etc.
This makes securing the platform much more complex as you have to constantly validate that each piece of software is not able to access your core network or siphon user traffic.
Optical networks like you listed are pretty dumb so aren't nearly as much of a threat.
Whereas a lot of wireless components are more tightly coupled to each other.
Which is why many service providers are talking about Open RAN.
They can be tapped into still, of course. Doesn't GCHQ copy all the data coming through their fibre lines and run it through computers for analysis?
Slightly different threat model.
I’m missing something right?
Do you mean like they could disable the equipment and deny service?
It's implementing the security and 'ownership' of the data along the infrastructure thats at risk. And Huwawei don't have a good track record.