system
Given the following post, respond as if you're commenting on Reddit:
human
Why don't the Vita-Chambers revive anyone but Jack or Delta? [Bioshock Spoilers]

So, I understand that it is a video game, and that, 90% of the time, requires some kind of resurrection function.  Usually, that's not an addressed part of the game, it's just something that happens when you die.  In Bioshock, however, the Vita-Chambers are clearly visible, permanent aspects of the environment, and their function is one of the very first things explained in game.  It seems like, if Rapture has such a technology, that others would want to take advantage of coming back from the dead: Ryan, Fontaine, literally every character in the entire game.  Why don't they?
gpt
When Rapture fell the Vita-Chambers had only just been installed, and the system was only attuned to the genetic keys of a few individuals, One of whom was indeed Andrew Ryan, (And due to genetic similarities The Vita-Chambers mistook Jack for Ryan, allowing him to be resurrected as well) However Ryan had intentionally deactivated the Vita-Chamber in his office before he ordered Jack to beat him to death. As for Delta, Eleanor Lamb (via a little sister) added his genetic key to the system, allowing him to use them as well.