But we live in a modern world, and the idea that birthdays are nothing other than another day is becoming increasingly common because it's no longer a true testament to our survival. We're almost guaranteed to survive another year til a point (In developed countries and to natural causes). So, with that in mind, birthdays have become less important in our lives. Well, I say that but there's still other rites of passage, such as 13, 16, 18, and 21 (in general, give or take a year depending on culture), that we do immensely celebrate. They're huge steps in our lives that propel us forward, so we tend to celebrate them more.
It's not about consumerism or anything of the sort, either. Presents now could have the point attributed to them, but that comes with the modern times. They, presents, have always been given but were not necessarily purchased.
So yes, birthdays are more of long-standing traditions that have lost the original meaning somewhat. But it is still there when you celebrate a person growing up. We just don't take it as serious, perhaps? That's a misnomer, however. We take them seriously in another way. But my advice is to celebrate them and celebrate them as often as possible, in whatever manner you (the birthday boy/girl) choose. (Not to mention a yearly celebration is great for morale and lifting up one's spirits).