The issue here is that the sister could have used ChatGPT herself, so why bother hiring the plumber. The plumber has provided less value than was expected. But make no mistake: the value the sister was looking for was to have someone else deal with it, and there's a price that the sister was willing to pay for the service of having someone else deal with it.

In the comments of this HN post, there is a dead comment from someone who posted an LLM's summary of another comment. It's dead because it offers very little/no value: that summary could be obtained directly from ChatGPT by anyone who wants a summary.

The sister offloaded plumbing to the plumber under the economic principle of comparative advantage. The plumber undermines the value they provide by outsourcing yet again. What value is provided by the middle man who does nothing but proxy the issue? Is the person who does this really a plumber? Is a plumber merely someone who has plumbing tools like wrenches and pipe tape?

That the plumber also wanted to outsource it is the concern: right now, the plumber is able to make money because of the difference between what is charged to deal with a problem and what it costs for them to deal with it. Knowledge and experience has become a commodity, which we probably can't do anything about, but along with that comes all the drawbacks (and advantages) of things, and humans, being comoditized.