If a person says that AI saves them 8 hours per week but they do not work less, their claim is that their output is 8 hours more worth of work in the same 40 hours.

Disregarding the lack of a baseline, I am genuinely curious as to where these hours supposedly go.

If the output of one person is higher does that mean that the input of another person is also higher? Likely so. In turn we can actually assume, in a digital world, that the increased output of one person can affect the input of many other people.

Now, if the people on the receiving end do not have tools that help them consume or manage this content faster, their workload has actually increased. They may lose hours of worth per week because of it.

So when people say they are becoming much more "efficient" thanks to AI, it's safe to assume this may be to the detriment of others.

A few people becoming more efficient does not mean the community becomes more efficient. Sometimes it's the opposite.