Better than no veggies or totally pointless???
In this order: Fresh local (best), fresh, frozen, canned.
Fresh local would have the most nutrients. Fresh would be next, but if the veggies had to be transported a long distance and have been sitting for very long, I might grab frozen. In most cases frozen veggies are blanched and frozen close to having been harvested. Canned would hold the least nutrients although I do buy canned tomates for cooking and also beans to have on hand when I don't have time to soak dried (altough canned beans should be rinsed before using). Knowing what I know now I no longer buy canned veggies outside of the one's I listed.
If you are cooking the veggies the difference between the fresh and the frozen ("fresh packed") would be very minimal.