Maria Raga never expected to be able to pull off a pair of yellow Versace pants like the ones she was wearing the day we spoke in July. Although she’s now the CEO of Depop, a popular clothing-resale app, she was hardly a lifelong fashionista. “Versace’s a brand that’s accessible for very, very rich people,” she says. “But I got it secondhand on Depop. It’s a very cool color. I can tell you nobody else in my circle of friends will be wearing something similar.”

Raga, 42, is not exactly in Depop’s core demographic: 90% of Depop’s 30 million active users across 150 countries are under the age of 26. She was skeptical of buying previously owned clothes after growing up in Spain on fast-fashion labels like H&M and Zara, br…