[O9A]

Chinese companies are forced to work with their intelligence agencies and are required to have mandatory backdoors into their devices

Who's to say that other companies don't do the same? Your IPhone may contain a backdoor, and you'd never know It.

This Is only what we're aware of through public exposure.

That is a good point, even if the OS itself doesn't contain the amount of old, old vulnerabilities which have been found over the last few years have raised my suspicion to be honest, openssh, flash. Did the developers really not know about all these bugs or was it more like if it's not broken don't fix it.