Anecdotally, having done multi-year deep-dive security reviews of both Asian and Western carrier equipment (and compared notes with many colleagues working on similar efforts), there is a stark difference. It's not even close. I've focused on firmware security analysis of RAN/eNodeB/gNodeB equipment but have also done many pentests targeting core infra as well. Western nations have actually done the baseline assessment over years and years of deployment and defence - this is why we are able to see the contrast in the comparison.