I often think of them as a tax on people who don't want to carefully tailor their shopping to line up with shifting "deals" across supermarket chains and over time and those who don't have enough storage-times-consumption to benefit from buy-n-get-one-free on kilo packs of margarine.
I don't think they are identical as such, because my impression is that points would not routinely exceed 5% of your overall shopping unless you got lucky or shopped very carefully, but these days "savings" from avoiding the punishment price regularly accounts for 5-10 pounds out of 100 pounds of shopping. Though maybe more people use the cards now to avoid it so it does average out.
I don't think they are identical as such, because my impression is that points would not routinely exceed 5% of your overall shopping unless you got lucky or shopped very carefully, but these days "savings" from avoiding the punishment price regularly accounts for 5-10 pounds out of 100 pounds of shopping. Though maybe more people use the cards now to avoid it so it does average out.