Gifts are just a nice addition that allows players to express their emotions. They carry no practical use, with the exception of the "Sapphire Peak", which increases the experience point gain:

and the "Sand of Time", which allows you to conserve your consecutive daily bonus streak if you plan to take a break from the game:

There is also an option in the game "Gifts from friends only" that will be available at the sapphire level of the loyalty program.

All the details about the loyalty program with the resulting bonuses and discounts can be viewed by tapping the window in the profile: