What I know is that, you are gambling if you would earn something from what you have put into something or you'd get something and your opponent will lose something. These two are the principles I believe of what gambling is.
I've never seen this type of game in the casino, maybe as I'm not someone who researches all the casino games, I just limit myself to making sports bets for that reason, I don't know if there are these types of games in the casino, but I I think OP you can explore other games in the casino in case you don't have that specific game that you want, but always play only games in which you have some mastery or that at least is a game in which you realize that you learn with some ease, because in the casino you easily lose money, something that can even lead to bankruptcy, there are many cases of people who went bankrupt because they did not have control over the game
Maybe tournaments? Well, it is somehow of a gamble because there is a risk of losing. But in tournaments, the fees are for the organizer of the event so it is more of paying a service. It is just the idea of putting money and getting more as return but as it goes deeply with the scenario, it could be different.
Likewise with play to earn games. An investor would invest money as a capital to earn more money from the game. Maybe it is the purpose or goal of an individual which makes an activity gambling and not the instance itself.