I quite like magic the gathering online for this purpose. You can’t trade cards, so the gambling and trading aspect go away. And you get wild cards in packs so it’s easier to craft the specific decks you want. Also the rapid cycle of releases just feels more fitting here. I’la be away for some months now and again and come back to an entirely new challenge of cards and decks.
I also paying is optional, you get enough resources just playing regularly that you join events and play drafts regularly. But you can also just pay to have enough to only play events if you feel like regular games become boring.
Just a point here, you're talking about MTG Arena, which is the new online game. There's a much older game still called MTG Online which preserves the gambling aspect, where you buy packs and event entries for real money as well as trade cards with other users (and through a number of legitimate third parties, even buy and sell singles for real money). They even go one step further: if you can collect all the digital cards of a set while they have physical product available, you can exchange the digital set for a factory-sealed physical print run of the set (https://www.mtgo.com/en/mtgo/redemption).
I kinda waffle between the two. Arena's my first love for the reasons you mention, but sometimes it's nice to simply buy some singles and throw together a (Pauper) deck for some fun on MTGO Online (especially since their set selection goes much farther back). I never play that one competitively, though. Feels like playing online poker against a community that's been refined down to 100% professional grinders or wannabes.
