There is an important fact your missing. Tests that are not correlated to anything is still useful data. Like say you're studying a person's concentration ability, you find their calcium levels in their blood has no effect on their concentration that's still useful data. Not as flashy as a new medicine that does improve it but it's still useful so you can elimate the need for more research in that direction.

She might just be saying that it takes a long time to run 1 sample, and it doesn’t feel like much got done by the end of the day.