Not strictly true. I have a couple of Lululemon gym t-shirts. 2nd hand, £10 each. They wick sweat brilliantly, dry out quickly, and don't stink if you have been wearing them for a few hours.
I wouldn't dream of paying full price, but the materials and build quality of the items are far better than the cheaper fast-fashion alternatives.
I know that's how I taunt my neighbours.