I’ve had pretty good experiences with buying and selling on it.
You get better prices as a seller on eBay, but Vinted is much less faff.
As a buyer, Vinted is great. I’ve kitted myself out with a whole work wardrobe of quality brands - Massimo Dutti, Cos, Zara, Calvin Klein, Ted Baker, Jaeger, Hobbs, DKNY, MaxMara - on a budget. Have to know what you’re looking for and your sizes in different brands, and I only go for ‘in very good condition’ items.