TBH though, I can't think of many things less fulfilling than wasting time on Facebook. The adrenaline from winning an online game, a show or film that makes you think or gives you a new perspective... then there's the Facebook feed.
I mean this in no offense, but you might be disillusioned or biased towards your particular vice. It's like an alcoholic telling me "well at least I am not doing heroin. Beer at least cleans out your kidneys!"
I struggled from video game addiction, and continue to struggle (it takes a lot of mental energy for me to simply not play). I used to tell myself, "well at least I am playing online and interacting with real people" or "at least I am sharpening my reflexes!"
For you, facebook. For me -- videogames, particularly online competitive style. For someone else? Bingewatching brainless television on Netflix.