If gratitude did not exist, then we would not do anything for each other, because the meaning of your actions in relation to others is lost.
Doing something about a person that gratitude bursts him from the inside, you begin to relate to yourself in a different way. By these actions we are trying to show and understand ourselves, to answer the question "who am I?"
Trying only for yourself, you will not be able to find the answer.
This is how an exchange of gratitude came about.
They say “thank you” to you so that you can understand who you are, and you thank so that others have the opportunity to gain the necessary knowledge about themselves. We cannot take and throw out any of the two directions, then the whole mechanism will stop working.
Good wishes for you this Thanksgiving!