Market
Cash is a trust instrument
Cash on delivery is not a payment preference. It is a trust instrument, and it is priced.
Look at what the customer is actually doing when they choose it. They are declining to pay a stranger in advance. They are keeping the right to open the box, look at the thing, and hand it back. They are accepting a worse experience, a driver at the door with change, a delivery window they have to be home for, in exchange for one guarantee: you do not get my money until I have seen what you sent.
That is not a habit. That is a position on how much they believe you.
For years the region's e-commerce ran on it, and a great deal of energy went into treating it as a problem to be engineered away. Prepaid discounts. Card-only checkouts. Wallet incentives. Some of it worked, the share of cash has fallen in the bigger cities, and operators celebrated the fall in returned orders.
But notice what the cash customer was paying for. Not the goods. The right not to trust you. Take the option away and the need does not disappear; it goes looking for a new home. Reviews. A brand a cousin has used. A shop with a physical address. A name that has been around long enough for the risk to feel small.
Which is the point. What replaces cash on delivery is not a payment method. It is a reason to believe. The brands that grew as cash faded were not the ones with the best wallet incentive. They were the ones the customer would have prepaid anyway.
The card is not the trust. The card is what trust lets you use.