The last point sounds like a standardization issue, not a technology issue. As for secure and robust - I assume that 5G must trade these for speed? I can't see how modern equipment would have less secure encryption otherwise. Assuming you are correct, which I must say seems like quite a stretch to believe right now, what would be the next format in mobile devices? A satellite service like Starlink? If 5G is completely standardized, then I don't see how the format could be fundamentally insecure on unreliable.Basically it is extremely overhyped, not to mention the very opposite of secure and robust. Which is a bit ironic given that one of the impetuses behind development of the technology, such as it is, was to try to salvage the dead end that is Cloud Computing. 4G is arguably the high water mark of mobile phone/device technology as we know it, and even that has struggled a fair bit.
Both the 5G hardware and software protocols & standards are an unholy mess, to put it mildly.