I've never used a meal kit delivery company but isn't the grocery market extremely cost-competitive? Retailers like wal-mart only make about a 3% profit margin

I've never used a meal kit delivery company but isn't the grocery market extremely cost-competitive? Retailers like wal-mart only make about a 3% profit margin. And that's with the customer taking on the picking, packing and delivery. Are meal kit companies really charging twice retail for the things they supply?