Avios are a money-printing machine for the airlines.

People love to look up the one-way unrestricted fare and use that large number to congratulate themselves on how valuable their avios were, but that's delusional. On competitive short-haul flights you'll be lucky to get two cents' worth out of them, ditto for long-haul biz class where I-class fares are available on BA or a competitor. (Don't forget to add the avios you -didn't- get because you didn't buy a revenue ticket to your cost for the award.)

If you use them for merchandise they generally appear to be worth a penny, but that comparison is to full retail, and if that same merchandise can be had at a discount you didn't even get your penny's worth.

The unsung benefit is that unlike paid fares to which BA likes to attach an exhorbitant change fee - 450 euro isn't hard to find - for award travel it's something like US$45 equivalent iirc. And cheap one-way biz-class fares are harder to find, so if you happen to need one, avios can be worth several cents (don't forget BA's surcharges in any case.)