Curate, connect, and discover
My take is that since gods are immortal, Styx can't actually punish them directly, but she can punish their children.
Thalia died once, lived trapped in a tree for at least 5 years before Kronos intervened in her fate.
Jason is dead on top of having a horrible fate in the first place, so that price has been collected.
And Percy fell into Tartarus, and his own life has been a terrible fate on himself, and I think the only reason he lives is because he dared to jump into the Styx, survived, and attained it's blessing or curse as you see it.
Not to mention, Hera intervened in his fate on sacred grounds past which the curse cannot extend. Even though he did lose the Curse of Achilles,Styx is all about oaths. Once blessed, always blessed. Percy Jackson alone has escaped the fate of a gruesome death. For now, at least.
Though I did read a fanfiction on how Styx enacted its revenge with it ending in all 3 demigods dying. I will reblog if I find it.
And the gods have eternity to suffer for; their punishment won't be instantaneous. Maybe this all sets in motion a revolt so great that the hierarchy of Olympus falls.
One thing that always made me wonder is how there doesn't seem to be any consequences to breaking their oath for Poseidon and Zeus.
Swearing upon the Styx is built up and treated like this really big thing all throughout the story. Everyone makes a big deal out of it- even the gods don't want to break them! So clearly there should be some consequences. Yet I can't help but notice there are none! Like, genuinely nothing ever really happens to Zeus OR Poseidon for breaking their oaths as far as I know. At least nothing that would genuinely damage them or hurt them. (I have seen somewhere that Kronos' and Gaia's rise were their punishments, though that falls apart when you remember those events were prophesized to happen before the oath was broken. Thus they had nothing to do with it.) Like genuinely idk whether Rick forgot about this or if I misunderstood something. But this seems like a PRETTY BIG PLOT HOLE TO HAVE-