PC games don't have such a service. Also for PS4, I'm not sure if the onlnie servers are run by Sony or the game developers themselves. If it's all Sony, then the PSN should cover it as you say.
The developers saw free to pay and pay to win games making yhem lots of money so they thought how can we add in pay to win elements in our full priced games. The loot boxes is what they came up with. Is this developer greed? Maybe. There is arguements to both sides here.
Online games are...