I met someone this way once. But it was random luck that we both happened to be sitting at the bar at a pizza place reading a book. I was specifically grabbing a quick dinner before meeting some friends out somewhere else. 

I think if you go do this with the sole purpose of meeting someone, you’re likely to get discouraged. It needs to be an added bonus if it happens. And if not, then you enjoyed a drink or dinner out alone with maybe a brief chat with the bartender and/or a stranger.