Have you always given a present to somebody when attending their birthday party?

All the time, if I were to attend a friend’s birthday party, I’d never be without a gift. I thought it to be rude if someone were to attend a birthday party and not gift the birthday person.

This is the first time that I’ve witnessed people going to birthday parties and not gifting the birthday person. They would help them self with all the food and stuff, have fun, but not give a gift. I guess it is true, that gifts should not be expected, but shouldn’t the person have gotten the birthday person a gift since they put in effort and money for the food and games?

Am I right to feel that that is rude? Would you ever attend your friend’s birthday party gift-less?