The founders of Depop have been in the fashion, and fashion retail, business for a long time. They started Retrosuperfuture, which was a cult hit in the sunglasses business (they probably did a lot more, but I never really bothered investigating). The knowledge and expertise they got from that cult hit — along with the credibility and the network among fashion’s “cool kids,” particularly in Milan — gave them a bit of an “unfair advantage” when they went after the at-that-time-already-getting-crowded used clothes business. They also executed pretty well in building exactly what their users wanted.
If you don’t get this business, how it is worth this much money, who they are, etc — no, you’re not some sort of genius humble-bragging that you’re blissfully unaware of such petty little things. You’re just demonstrating that you feel compelled to comment on things you don’t understand and dismiss them because they don’t fit into your myopic worldview of “what’s important.” Fashion is an industry, and one of the largest in the world; anyone who cares about global commerce / the environment / etc should be paying attention to that industry, and to the “circular” trend that remains in its infancy.
I hope the combined company continues to innovate, and that this isn’t just some sort of depressing market consolidation play. This space has a LOT of room for growth.