On a scale of 1-10.
1 = makes me more miserable (e.g., I'm addicted; it takes up time I could spend on RL friends; breeds envy, etc.)
5 = doesn't really have an effect in either direction, or effects are equally balanced positive and negative
10 = massively enhances my experience of life (e.g., alleviates loneliness, broadens my perspective, gives sense of community, etc.).
Obviously the reasons will vary widely. But what's your number?
I'd say 7.