Hyde here from Shopify. Interesting question!
We use the Billing address to help check orders against card details to notify you of suspicious and potentially fraudulent orders. There's more information on that here. Essentially we look for indicators that the order might be fraudulent by checking their billing details against their card details, as shown below:
You'll see that the customer's billing details are important, even if they are paying for cash on delivery. Incidentally, if you are based in India you will likely find the Advanced Cash on Delivery app useful. All that said, it is possible to edit certain field elements of the checkout process to simplify for your customers by going to Settings > Checkout in your store admin:
There's more information on editing your form options right here. You could always offer an explanation to your customers in the product description itself, saying that you need to ask for the billing address for verification purposes. Alternatively, you could edit the language of the checkout fields to further explain why a customer needs to input their billing information anyway, although it should be fairly self-explanatory to them already:
There's more information on editing the language fields here.
I hope this all helps!
All the best, Hyde.
Hey Hyde, thanks for your quick reply.
I am not sure I understand how the billing address is useful in this case. For cash on delivery, the billing address is always the shipping address. At Least that is the case for our business. I have set it up so that the billing address defaults to the shipping address, but it is one more thing that the customers have to go through during checkout that is entirely unnecessary. I wish that there was at least the option to disable it for COD.