A card that was ideal before marriage, relocation or a new job may become poor value later. Recalculate when travel decreases, fuel use changes or major bills move to categories that the card excludes. Do not keep paying an annual fee because the card used to be good.
For a points card, record how many points you actually redeemed in the previous year and at what rupee value. Unused or expired points have zero realised value. For cashback, check whether monthly caps prevented you from receiving the advertised headline percentage on most spending.
When comparing two cards, include the value of simplicity. A slightly lower reward that arrives automatically can be better than a theoretically higher reward requiring portal bookings, transfer partners and expiry tracking. The correct winner is the one that produces the most value in your real behaviour with the least extra spending and friction.