In Realm Reborn they keep mentioning that you can safely entrust your gil to your retainer. What is that supposed to be for? You don't lose gil for dying, I think.
I know that retainers can have their own gil balance, because you need to retrieve the gil you got from selling items – so withdrawing is ok. But why deposit?
Best Answer
Being able to give gil to your retainer is likely just a holdover from version 1.0 of the game, where retainers would more directly carry out buying and selling items in the markets on your behalf, so there was actually a purpose to giving them money. For example, you could set up your retainer with a stash of money and a "buy" order, so that other players could choose to sell items to your retainer for an offer price that you set up ahead of time. Likewise, for a period of time you could put your gear up for repair with your retainer, along with a gil reward for any players that repaired that gear.
Although it currently serves no necessary purpose right now, some players like to use their retainers as a piggy bank; a place to squirrel away money so they can't impulse-buy things from the market wards as easily. :)