This weekend I noticed a curious feature of Total War: Arena. If you play the game with a free account, you not only earn less xp, but silver is also tight, so you can only afford the necessary unit equipment. If you play with a premium account, you get a lot more silver (because the gross amount before expenses is increased, leaving a much larger net amount). And there is nothing in the game you can do with that silver, except for buying consumables.
Consumables, as the name suggests, only last for one battle. There are a couple of fun ones which give you a very short time effect, or allow you to build a trap or barricade. But there are also consumables which simply increase your stats for the whole duration of the battle. You can set those to auto-replenish, and get the effect in every battle, at the cost of silver. As a result, with a premium account you can play with consumables all the time and not have any money problems. With a free account you can only afford them once in a while. So in the end the premium players’ units have better stats than the free players’ units. But it is very discreet and not widely advertised. Hidden Pay2Win.