[Someone]

https://en.wikipedia.org/wiki/Code_signing#Unsigned_code_in_...:

“Most console games have to be signed with a secret key designed by the console maker or the game will not load on the console. There are several methods to get unsigned code to execute which include software exploits, the use of a modchip, a technique known as the swap trick or running a softmod.”

I don’t see how iOS is different here.