It was replaced by the 9x18 which had superior stopping power (if we are to use this term) against humans.
This was because the 7.62x25 had far too much penetration power and left most of its energy somewhere behind a human target. The 9x18 deposited more of its energy in the target. Sure it penetrates car doors but who's doing this with a pistol? You can also produce a cheaper blowback pistol to fire the 9x18, whereas the 7.62 requires a more complex locking mechanism.
Still good for sub guns? Not compared to the 7.62x39 and 5.45x39 which replaced it in the submachine gun role.
It's better than some things but in the context of what replaced it, it was logically doomed.