There is a large amount of $$$ that goes into security of iOS and iPhone (sometimes orthogonal to privacy, sometimes not) that does not go into a dumbphone. The iPhone is also much more scrutinized and researched into than a random dumbphone, so it is plausible that you get much more exposure to exploits, etc., using a dumbphone that does not get updates etc.
It seems unlikely they put the same efforts into finding a zero day for a nokia. There might be a super easy to find zero-day though, like you're saying.
There were always obscure pieces of software that would pull your forgotten pin right off the device with the right secret code, in which case you have full access to the device.
I'd also expect them to be vulnerable to much simpler attacks like just reading flash chips directly
What's your threat-model? If your adversary is a nation-state on par with China, you're probably toast unless you have a well-resourced entity supporting you (think large corporate or another nation-state)
The dumb phone has no access to the pocket computer, after all.
edit: In a laboratory environment, it is probably easier to break into a dumbphone vs breaking into an iPhone, yes.
I can't tell you which results in better opsec today for say carrying out government-disapproved commerce. But I can tell you that the privacy benefits of having a bona fide computer that you control in your pocket will continue to grow, while the cell network is stuck being forever subservient to government/commercial surveillance.
This is true. But I'm not a privacy absolutist. I'm willing to sacrifice privacy for some things, and having a phone is one of those things.
But that I'm willing to put up with that from one company in no way means that I'm willing to put up with that from other companies.
> switching away from a smartphone is probably useless if not counterproductive.
I don't see how -- can you explain? Reducing data leakage seems useful even if I'm not completely eliminating it, and I don't see how it's actively counterproductive at all.