At this point, nobody else does on-device scanning.
If on-device policing is the best option going forward, then we are already living in a dystopian society. In a world where the majority is ok with this kind of functionality, discussions about privacy and personal freedom becomes pointless.
That’s a dangerous way of looking at it. Most folks are careless, they will buy any kind of crap if the wrapper is shiny enough. Legislations and customer protection groups are what is supposed to prevent such situations but the system is simply not working.
I fear that after some initial outrage people will calm down and the protests will die out. Google and Microsoft will implement similar systems next, and users will follow out of convenience. Linux community will resist but Linux is practically unusable as a desktop system, so nobody will really care. And within a couple of years, we will live in a total surveillance society, where our own phones are spying on us.
The real danger is lack of functional legislation and proper law enforcement mechanisms. Apples technological platform is sound and well implemented. It’s much more sophisticated than other systems and it does put user privacy in foreground. Unfortunately, Apple seems to be completely oblivious to the social aspect of the problem - imperfect data sources, flawed legal system, dehumanized law enforcement and of course, nefarious actors that will find a way to use these systems to their advantage. Forget ransomware, now you have to fear receiving manipulated images f cats that will get yiu flagged as a sex offender to a system that does not give a damn about you as an individual. Read about folks who had their bank accounts locked because they share the same name as some criminal. That’s how well the system works.