So... for mammals, play is most definitely not "merely entertainment" in general. Watch any puppy, kitten, or human child - play is a way to train and hone various skills and thought processes. It is a way to engage in complex behaviors and activities at low risk to develop abilities in youth and maintain them as adults.So what you're saying is that, just like Monopoly, we can just say it's a game, and therefore meaningless?
Thus, in a broad sense, it would seem blithe to say that games, broadly, are meaningless.
Moreover, popular game products have a context in culture - they are cultural artifacts, just as any novel, movie, or artwork is. We can point to any number of cultural artifacts that have had great impact, both on individuals and on cultural direction. So, again, to generally categorize this stuff as "meaningless" would seem like wishful thinking.
I can understand that folks often want to be free of all that - "Just let me noodle meaninglessly with my friends about the dining table, please!" And, while a given entertainment is small, its overall impact is more limited. As things get popular, I'm sorry, but the folks who produce it have to think of their work as having greater cultural relevance and impact, and what is in the product comes to matter more.