Magic Online simulates paper Magic. You buy packs to get cards, each card is its own individual digital object which can be traded and sold, card sets go out of print or have limited runs, and rare promos are released. It even has its own digital currency, "tickets", which are reasonably easily converted to cash.

Magic Online accounts can be worth tens of thousands of dollars.

And at least back when I played, if your account got compromised and all your cards were liquidated, the response from customer support was pretty much "that's too bad, shouldn't have let your account get compromised". I seriously doubt they ever added 2FA or anything either.