They are predatory because people are LIED to.
I don't remember seeing anywhere on any loot box saying "buy this lootbox and get this item" unless it literally gave you that item.
But you are reaching instead of admitting even a iota of possibility of being in the wrong.
I gave no definition
But your definition makes employees who ask for a promotion predatory towards an employer who cannot let them go.
Lootboxes don't exist on a spectrum (MMOs do). They are a singular mechanic. Which is essential for lootbased games.
Your beef is clearly with the business models. But until you agree that lootboxes are essential and awesome we cannot get to the meat of your problem