We must return this to the notion of gambling which involves betting in a game. So in general if a game is without betting then it cannot be said to be gambling in my opinion, because it goes back to the basic understanding of gambling itself. And I agree that gambling carries risks, and if there is nothing at stake then what risks will we get, because we don't bet anything and will not lose anything from that game.
However, if it is based on personal opinion, of course there will always be different opinions from one to another.
Didn't gambling start back then when money was not created yet and other things were paid when a gambler lost? Because I remembered when I was young, I was still in elementary school, when I was playing with my friends in the text card battle of marvels super heroes, when I won, I got a card instead of winning and when I accumulated a lot of cards, I sell cards to my opponents or teammates to make money for a small coin.