But there is a vast gulf between humans, even those with severe developmental disabilities, and the smartest animals. Only a handful of animals can even pass the simplest knowledge to other, or learn by seeing others of their kind do something. Humans can't even function if we don't use language to communicate with others about things which aren't pressing concerns. There is plenty of room in that gulf to say THIS side is conscious and THAT side is not. Just like an analog-to-digital converter can get clean 0s and 1s out of a continuously varying noisy signal if it is sufficiently clean, but we don't claim that digital electronics doesn't exist just because there is some spectrum.
I do agree that there is some continuum of conscious experience between certain animals up to humans. I even believe there is an extremely remote but real possibility that other organisms such as plants, fungi, even bacteria, have some sliver of internal life that could resemble our consciousness.
But panpsychism goes WAY beyond this into a mush that makes no sense. Rocks and atoms very obviously are not conscious, and any non-religious theory of consciousness that posits that they have to be, even a tiny little bit, is in my opinion self-evdiently wrong (e.g. IIT).
Of course, if we want to posit that some form of god exists beyond physical phenomena, panpsychism is valid again.