Sure, maybe it costs a little more, but think of the benefits: You can wear specially treated or constructed garments that don't stink and don't require a lot of washing. It's good for your wallet and for the environment, right? Not to mention whoever gets to avoid smelling you.
It's not that simple, though it's easy to see why it's so alluring. Journalist Alden Wicker, writing for Vox, breaks it all down scientifically, economically, and psychologically. So-called "washless" clothing is usually made with an ecologically appealing material, like merino wool or even seaweed, or it's been dipped (so to speak) in an antimicrobial compound, like silver or peppermint oil. Wicker finds that many of these items tend to perform well; however, there are downsides that may wash out the benefits.
Silver, for instance, doesn't guarantee a stink-free after-workout glow, and silver nanoparticles can leak into water supplies as pollutants. While natural fibers can whisk away your BO, they can also get really pricy; Wicker found one white T-shirt that cost $85. But there is good news.
Most of us don't actually stink as much as we think we do. In other words, we can smell ourselves, but other people don't tend to notice. You've also got some tried and true money-saving options for airing out your clothes between washes, including spritzing with a vinegar solution. And finally, while there's certainly something to helping your wardrobe last longer by spacing out washes, doing your laundry is one of the best ways to deter some very unwanted pests.