I basically mirror Thomson's opinion but there is are other frames on the thinking. Eg, as paying someone to demonstrate a deep understanding of a topic and articulate the uncertainties. That is different from traditional research because they aren't being asked to do anything exactly new. But in practice that is what I think the better researchers actually do.

Maybe there is a clue in the name "re-search". Epistemologically I don't think it is possible to set out to discover something that isn't already known to exist, so the justification for paying people would best be for evidence that they were searching rather than if they find something.