Janeway said that the Prime Directive applied in Prototype.
AI utilizing a technology generations ahead of Starfleet that was pwning Voyager.
Of course the Prime Directive goes both ways, applying to more advanced races screwing the federation over. Being nice to the younger races is about the best way to prove to the older races that you're too nice to be fucked over for no reason.
Although even if a world is more technologically advanced, Janeway can still contaminate them with culture and philosophy, like in the case of A Piece of the Action. Look what one book did. I mean Janeway would never just hand over an entire book like that and walk away never considering the consequences of her actions.
Besides Kodos, if you're talking about keeping the Array out of the Kazons hands in the pilot, the Prime Directive said that the Kazon were supposed to get it, Tuvok says that on camera, and breaking the Prime Directive was to stop the Kazon getting the Array, which is still what Tuvok said but a little more clearer, is bad and criminal and wrong. It is the natural development of the Kazon to take advantage of valuable salvage, and Janeway broke her own laws to stop them, to cancel Christmas, because she didn't like the possibility or what she thought that they might do with that technology maybe. She didn't like the consequence of herself doing nothing, as in what would have happened regardless if she wasn't there... if she was really concerned with the Kazon murdering and enslaving little cow species, then she should have killed them all. Her half measure was insulting to every one else in the quadrant being oppressed by the Kazon who Janeway left in chains, including her own crew two years later.
The only way that Janeways decision made sense was if she was severing all bonds with the Federation and aligning herself with some hypothetical quasigreatergood manifestation of the Delta Quadrant inhabitants of which she was it's chief moral arbitrator... Because that's what "being involved" in local politics means, when you have no damn idea what the local politics are, rather being a disinterested foreign interest who doesn't believe they want to be responsible for idiots acting idiotically and every one else paying the cost.
Ijust want you all to remember that Janeway said that she had NEVER broken the prime directive in Equinox, but later...
KASHYK: Are you sure you'll be welcome when you do? I came across something else in your database. The Prime Directive.
JANEWAY: The Federation's cardinal protocol.
KASHYK: It seems you violated it when you rescued these telepaths.
JANEWAY: Well, let's just say I usually go with my instincts and sort it out later at the Board of Inquiry. Those Admirals and I were on a first name basis, you know. You're risking a lot, too. Why?
She's saying that she's above the law because she knows people.
And really, if the Prime Directive applies to the Devore Imperium, a race on par with the Federation, at least in terms of technology, then it applies to everyone.