Very secure means high-assurance for both hardware and software, very insecure means no assurance for neither hardware, nor software, with control over system b

Very secure means high-assurance for both hardware and software, very insecure means no assurance for neither hardware, nor software, with control over system belonging to multiple third parties and what not, basically consumer stuff. And threat model for this consumer stuff just doesn't include an adversary capable of intercepting all of your communication and cracking less secure protocols, this is just silly. Because with such level of capabilities an adversary can just target a whole bunch of third parties that have control over your system, penetrate one of them and push a fake update to your system with screen grabbing malware or whatever. By the way, this is an example of a real world attack.