Perhaps the biggest difference, to me, is that when you buy a CCG booster pack, you can resell the individual cards (the publisher cannot forbid or, realistical

Perhaps the biggest difference, to me, is that when you buy a CCG booster pack, you can resell the individual cards (the publisher cannot forbid or, realistically, attempt to prevent this). When you buy a loot box, you get some bits set on your account with the loot-box-seller. You can only resell them if the publisher lets you, and only via publisher-approved methods. The reason this is a meaningful point of difference is that you no longer have the "I want X, and the only way to get it is to keep buying loot-boxes and hope". If you want a specific M:TG card, someone is happy to sell it to you for the right price; you don't have to dig through booster packs.