More retainers means more ways to earn Gil. With more Gil you could easily buy all the necessary materials that you need to craft or let others craft the gear that is needed for the new raid. With this new gear that you have really fast you then can try to tackle savage which will give you an advantage to all those that did not have the gil thus did not buy the stuff. Yes people can make gil even without that but its still easier when you are already good at doing Gil and get more options to do so. There was a thread a bit ago about a player that sells huge amounts of things thanks to gathering bots. With the app and real life money he could change the MB prices much more without needing to be in the game.
I mean any other P2W boost only helps someone get something easier. It does not stop others from getting there without that. The same with extra retainers and the app. You can still get a lot of gil without it but if you had them you would probably make even more gil and that faster. Doing something faster thanks to retainers and the app can kinda count as a win too. You win more time for others things.
(Also its a shame how people cant really stay on topic and have to attack the OP just because of other topics. This is not a troll topic so it should not attacked like one. Either post your opinon about the topic without attacks or just ignore it.)