No, because the quality of life is not similar. I think the parent of your post implicitly used that quality of life and poverty rates between the two are (relatively) comparable.

How comparable, exactly? If QoL in California is better in proportion to the workforce disparity then the UK isn’t any more efficient. If it goes the other way then the UK is even more efficient. Assuming they’re the same doesn’t make any sense.

If they're more or less the same, then assuming they're the same makes perfect sense.

That depends on how close “more or less the same” actually is. Within 10%? Sure. Within an order of magnitude? That would swamp the other difference.

I have no idea which way it is, but spinning lower GDP per worker as more efficient doesn’t make any sense to me.

>spinning lower GDP per worker as more efficient doesn’t make any sense to me

Well, the GDP doesn't make any sense either. Busywork also increases the GDP.

Does the Central African Republic have a comparable standard of living to the UK and California?