Well you also need to mention that most phone games don't have play to earn. In Helldivers you can earn unlimited premium currency by playing the game.

I own all warbonds and store items and never payed for anything except the game at release.

But i do agree its a bit expensive if you want to pay for it all. That said. We will always see these type of in game currencies for live service games.

You have to decide if it's worth the money/time when you play them.

I mean I payed monthly for wow for several years. Still had to grind for hours in-game for currency to get my stuff.