They prevent jailbreaking by not providing a way to do it.
They additionally prevent jailbreaking by patching vulnerabilities.
Only one of these things is being called out.
You can get into all sorts of theoretical discussions about how if there was a way to do it, they'd be increasing their attack surface since now they have to make sure this path is locked properly when the user doesn't want it, but people act like the only way for jailbreaking to work is for Apple to stop patching 0 days, which is not the case.
They additionally prevent jailbreaking by patching vulnerabilities.
Only one of these things is being called out.
You can get into all sorts of theoretical discussions about how if there was a way to do it, they'd be increasing their attack surface since now they have to make sure this path is locked properly when the user doesn't want it, but people act like the only way for jailbreaking to work is for Apple to stop patching 0 days, which is not the case.