How "unhackable" is your iPhone actually?

How Safe Are We?
The Silver Sparrow Virus
Bug Bounty
In 2019, Apple made the bold move to promise a million-dollar award to anyone who could hack their iPhone—but perhaps they needn't have gone that far. A similar stunt was pulled by bug bounty firm Zerodium in 2015. An unidentified team took on the challenge and promptly won the million by hacking iOS 9. They achieved this by carrying out a complete and remote browser-based jailbreak enabled on the inside by getting the user to open a bugged link or message—a vulnerability for which Apple was sure to pay more than the bounty sum. The bounty posted by Apple in 2019 hasn't been claimed yet, at least not to anyone's knowledge. But it's very possible that those who can are after bigger game.
Zero-Click Hacks Are a Real Thing
When Jeff Bezos' iPhone was hacked last year, it became clear that Apple's famed mind-bogglingly complex security systems could well be its downfall. Once an intelligent enough virus or malware finds its way in, it can be easy for it to remain there for a long time undetected, beneath the endless lines of code.
Apple Likes to Keep Mum
The fact that Apple deals with its security patches and strategies in a highly secretive manner, rarely disclosing details, adds more layers of uncertainty to the issue of iPhone software security. How safe are we actually? If some part of our phones were currently compromised, should we expect to be informed about it? Clearly information on exploitations or possible breaches of iOS privacy or security are million-dollar matters tossed between the top dogs.
By the way, it's good to know that Apple will never call or message you about a security breach. If you are contacted in any way by someone claiming to be from Apple, telling you you've been hacked, it's most likely a phishing scam—never click on the links or give any information.
Of course, it goes without saying that any jailbroken Apple device loses many of its security features and is automatically at greater risk for infection. Yet the majority of iPhone users will not find this relevant, having chosen to give Apple their money in exchange for its promise of simplicity, stability, consistency, and—perhaps most importantly—security. But one must always know that "what happens on your iPhone stays on your iPhone" may not always be the case. Although Apple certainly has one of the most high-end security systems, perfect safety is difficult to guarantee these days.