“Envy” in the sense of (or translated into) “competitiveness” or “incentive” can be useful.
Socialism, on the other hand, is about simple jealousy and, except in rare circumstances, generally denies the incentive to be productive or competitive, or to strive for improvement which leads to society of general mediocrity, at best.
If someone sees his neighbor really enjoying his 100" television set, decides to set about getting one himself, and feels glad that the world has provided him with such a goal to strive toward, I would not consider that envy. Even if his desire is, to some extent, to "keep up with the Joneses", if he is made happy by the challenge rather than annoyed at not having met it yet, that isn't envy.
I would regard envy, rather, as the feeling that one is 'owed' something--that one's lack of it is 'unfair'. In short, the fact that the neighbor's possession of an item one lacks makes one miserable rather than happy.