Neutrinos from Deep Inside Earth Provide a New Picture of the Mantle

Every time I see a story like this I wonder what happened to the small neutrino detectors enabled by coherent elastic neutrino-nucleus scattering [1] [2]. I'm guessing that these detectors aren't useful for a lot of the types of neutrinos that are interesting or something? If small, cheap, detectors like this were plentiful it would open all sorts of observations into the sun and the earth's core, exactly like this article is discussing. There must be something holding that back.

[1] https://www.science.org/content/article/milk-jug-sized-detec...

[2] https://arxiv.org/abs/1708.01294