I saw this article on news.com.auand I thought it would be worthwhile sharing here. The bottom line is that for most of the population they would be better off with a no fee, no points, low interest card.
I confess, years ago they did offer value and I have had many "free" airfares and upgrades. But now with the low earn rate, high surcharges and reduced opportunity to use points, they encourage the user to make expensive and poor decisions in the hope of an upgrade. A similar psychological stimulation to gambling.
To use points prudently, we all know that you only use them for upgrades because the out of pocket surcharges make using points a waste of money. But to have any hope of an upgrade to Premium Economy or Business Class you have very little chance buying the cheapest economy tickets because the full price and flexible ticket holders are before you in the upgrade queue. If it weren't for points Qantas would not have the "loyalty" they currently have. A consequence being more travellers would support other airlines and Qantas would reduce their fares to be competitive.
On the purchasing side, we would not tolerate surcharges for credit cards or ask for discounts for cash or debit cards.
The bottom line is that for most people having a credit card to earn points is a wasteful marketing trick.
They cause the user to lose money that they would not have if they weren't a credit card user.