A gift is an investment in a relationships
You've heard that investing your time and money is wise, right? You invest in technology companies or grocery stores, because you expect a return on your money. You put in $50, you get out $75.
One of the many reasons to give a gift is because it makes a return. It shows someone you care. Then one day, you might need something and that friend has your back.
Giving a gift doesn't buy their friendship; it helps to strengthen it.