IOS device security

Since joining I’ve seen many responses to worried users saying if your iPhone hasn’t been jailbroken and haven’t given anyone access then you can’t get hacked, so it’s very reassuring to read this, particularly from long standing, trusted community members. However, apart from compromised iCloud accounts, I would really like to understand more about device security in general. In particular why there is always so much information on the internet saying that an iPhone/iPad CAN be hacked. Even reputable websites and news pages seem to state it. Is this just lack of knowledge? Or is it just making reference to the one off occurrences like Pegasus for example that is very expensive but would never affect the man in the street? I would like to understand more about what a “hacker” uses to potentially take over a device (if that is actually possible). Is it just usually an app they try to get you to install? Or do they use other mechanisms that are less detectable? Or simply if your phone isn’t jailbroken it’s safe what ever you do because a non-jailbroken phone will just reject any form of malicious attack? My devices haven’t been jailbroken and I have 2FA on my accounts but like a lot of users paranoia often sets in and “googling” for answers probably isn’t the best solution.

Many Thanks