Most gambling addicts start off with something that is just "kinda a joke" like betting on soccer etc. People have studied that gambling addicts do it because they get a serotonin response when they gamble (dosen't matter if they win or lose - its the act of doing it that triggers a response).
Any sort of lootbox system offers an outlet for this aswell. How does this not serve as a gateway when the things you get from lootboxes have actual real money value like resellable skins?
Noone has but any effort into figuring out who "whales" actually are, they are however building games around the idea that these people can whale over others - spending money in games to be more powerful than people that don't.
Who are the whales? Are they children? Are they mentally ill? Noone is putting serious effort into mapping this.

With pay to win you are bringing peoples real life situation into the gaming world - aren't games meant to offer you a fantasy where you can do what you want?

Noone knows what the consequences of using abstracted currencies such as "gems" etc. in games. We have never had more young people seriously indebted in the western world, but this could be many things, availability of loans etc. But if it is partly because credit cards have abstracted currency spending, you are feeding into this system with even more abstracted currencies. Today children have phones with games that offer IAPs, and noone knows how this could potentially affect their spending habbits in the future because it is new.

The thought of feeding into this makes me feel sick.