Dropshipping is one of those models where there isn’t really a cap on how far you can grow it.
From what I’ve seen, one product/single category stores scale way better than general stores. With a focused store, it’s easier to test ad campaigns properly. But when you run a store with multiple products, it gets really hard to give attention to every product. Each product has its own competitors, and standing out against so many competitors is tough. You also just don’t have enough time to build a solid marketing strategy for every single product.