I'm a very specific person when it comes to who I will call a "friend". Having said that, most of my best friends are people I've known since I was about 12 or 13. We were best friends through Junior high, high school, college, and still make time to see each other now that we're all graduated and don't live quite so close. We're all 24-26 now, and we've just stuck together for so long. Of course we've all got other friends we've met along the way, but the core group of us have just stuck together and always gotten along so well. I feel very fortunate to have such awesome friends.
Most of us live within an hour or two of each other, and some out of state. But we still make time to get together as often as we can. Most of us are in long-term relationships, and a couple are even married (no kids yet), but any chance we have to get together and do something -- we do it. My girlfriend and I host a burger night once a month, where we invite them all up for a night, feed them burgers, beer, and whatever else. Spend the whole night laughing, and just enjoying each other's company.
Once a year we get the WHOLE group together, and go on a weekend-long camping trip. The out of state friends make the trip home, and we spend the weekend together. Grilling, tipping 'em back, and just shooting the shit. It's easy to stay in touch via SMS/Facebook/Email/Phone, so we all stay pretty well connected. And when we see each other, it doesn't matter how much time has passed. It's always just like old times.
Love those people. I'd do anything for them, and I know they'd do anything for me.
So no, friends are not useless. Perhaps you use the term 'friend' a bit too loosely.