There is plenty of risk involved with trying to crack an iPhone and the software that comes with it. When asked about the possible success rate, one team member said that it largely has to do with how “lucky” they get while working on it. In the end, any jailbreak that gets published and is usable is one where a team of developers got lucky when putting everything together.
Companies like Apple are trying hard to keep their software a secret and would prefer that developers are not poking around in it allowing access to all of the channels inside for consumers that take the risk of jailbreaking their smartphone. Most would not recommend that you jailbreak your phone because it will end any warranty on it and it could cause your phone to become un-repairable, or “bricked”.
For some that is quite a lot of money to toss aside just to take a look at some custom software, but for others, it is the thrill of gettign something passed a large company like Apple.