Imagine a fairly boring interface that has Pokemon cards or football stickers in. Like your hands holding them and trading them and sticking them on things.
Now contrast that to the loot box stuff that has exciting music, flashing lights, A-B tested into oblivion, the money comes from some ethereal 'account' rather than involving an actual exchange, etc.
I think the analogy is more with the flashing exciting slot machines at the pub (which seem to have evolved a ton since I were a small as well...)