There is no certainty that Amazon will find against you for INR, but it seems to be the majority of cases.
Certainly reports of INR fraud are high, but of course the feedback on the forums is biased - people will rarely come here to create posts saying they successfully defended an INR, just to ask for advice how to appeal…
You are right, claiming against the courier with buy shipping is harder and more convoluted, if not downright near-impossible. However, even if you buy your own shipping via a 3rd party courier, they generally wouldn’t refund you or pay-out if their systems show the delivery made properly.
I understand your point but I think that is a little extreme. Businesses do suffer from online fraud of one type or another, but there has to be some loss built into your pricing and revenue model, just as a high street shop will have breakages and shoplifting built into theirs.