In all seriousness the chain measure is a better one. Chains for some riders last 2-3 times as long as for other riders. That is based on dirt, lube and power. Which is the same stuff that wears out a cassette. I've had 4 tandems and the ratio was about the same on them - although everything wore faster.

And - FWIW - larger cogs wear things less. So a 13T-28T with big rings is less wear than an 11T-28t with smaller rings - that is if you use the 11-12T.

Then if you cross chain a lot, that wears things.

Too much lube collects dust.
Too little lube increases wear.