Nice AI-generated images, OP.
For a similar reason to Space Marines, I think catfolk in 40k are just boring. There’s so much cool stuff to explore and yet people continually gravitate to the familiar.
I think the Troth are an interesting example of an abhuman that should be explored further. A race of humans that have somehow merged symbiotically with the flora of the planet they inhabit, to the point that they cannot leave without severe consequences - perhaps a less grimdark version of Catachans.