MTG Arena - there's a regular play queue and a ranked queue, and people definitely play to mess around and try new decks for fun. This of course doesn't cease to induce salt from sweaty gamers in the play queue.

Even ignoring games that you consider "in the gray area," who are you to say someone can't find a way to have fun in a game that doesn't align with your way of having fun? Not everyone is playing the game hoping to land on an esports team.

Edit: I'm mostly referring to casual queues - ranked queues being hyper competitive does make sense. I've just seen the same argument made that casual queues should be the same level of competitive.