What we need is for legislatures to pass "NO Chat Control" and "NO KOSA" bills that specifically block this behavior, but unsurprisingly governments don't seem to be too keen about limiting their own rights, only those of their citizens.
Make a law that says companies have to protect the data of their citizens without the possibility of any intentional backdoor, perhaps. Make a law that says companies can't require people to dox themselves with ID scans simply to use a publicly available internet platform that provides no services in the physical world. Make a law that says OS developers can't create client-side scanning services that upload results off-device without revocable user consent.
The EU does not seem to have such simple and ironclad norm.
For reference, the EU does have an equivalent norm: https://fra.europa.eu/en/eu-charter/article/7-respect-privat...
In comparison to the US constitution, EU "norms" might as well be toilet paper. For example, they have some notion of "free expression" which sounds like free speech but is defined to be so weak as to be useless. The european public broadly does not seem to care, they certainly aren't willing to kill for their rights.
Leaving aside everything else wrong with it: in the absence of due process, that can happen to citizens too.
It might be interesting to go the other way: Get it put into the constitution of a major country that these kind of backdoors are banned world-wide and you can't do business in that country if any part of your enterprise implements them anywhere else.
To begin with this would make it harder to pass laws like this in other places -- domestic companies with international operations would put up stronger opposition because it would compromise their ability to do business elsewhere, and legislators might actually be concerned about that. And then on top of that it would force the companies to choose which subset of the world they want to operate in, allowing people in oppressive countries to pick up uncompromised devices from the places where compromised devices are banned.
Since decades.
Pass your 'no KOSA' law. And then when they want KOSA, they just pass KOSA with a sentence that says this KOSA law supersedes prior 'No KOSA' laws.
You need to limit their power to do that and the only way is constitutionally.