Timing is the main problem. The evidence that wins disputes is easy to export when the order goes through and often gone six weeks later. It includes three things. The first is the AVS (billing-address check) result from when the bank approved the payment. The second is a record of the buyer's device at checkout. The third is the customer's login activity in the days after delivery.
The merchants who win most often store the right fields against every order when it is placed. AVS results sit in the payment company's record (Stripe, Shopify Payments and the like) and are never joined to the order in the merchant's own system. Analytics tools drop device records after 30 to 90 days. Nothing links login activity after the order to the original order.
See your dispute rate on each card network. Install Predispute free on Shopify.
Most order management platforms expose webhooks. One at order creation and one at fulfillment can push the six or seven fields you need into a long-term table indexed by order. A few hours of engineering pays off the first time a dispute needs them.