This is a fair question. The closest answer I can get is eyes and ears onboard complement sensors.
True. I wasn’t thinking about training the ground crews.
This is not just training the current flight crew and ground crews, but is also generally testing the entire system - including operations and hardware too, with feedback important to logistics and component manufacturers, etc. With possible exception of Falcon 9 launches, space missions are still infrequent enough that each of them is providing knowledge and experience meaningfully relevant to all work in and adjacent to space exploration and space industry.
> Apollo was over three orders of magnitude more efficient in producing scientific papers per day of fieldwork than are the MERs. This is essentially the same as Squyres’ (2005) intuitive estimate given above, and is consistent with the more quantitative analogue fieldwork tests reported by Snook et al. (2007).
Scientific papers are a pretty poor measure of productivity so here's another one. We know about the existence of He-3 thanks to samples brought back from astronauts on the moon. Astronauts setup fiddly UV telescope experiments on the moon, trying to set up a gravimeter to measure gravitational waves, digging into the soil to put explosive charges at different ranges for seismic measurement of the moon's subsurface... They were extremely productive. Most of what we know about the moon happened thanks to the 12 days spent on the lunar surface.https://en.wikipedia.org/wiki/Far_Ultraviolet_Camera/Spectro...