I believe that “all is physical”. We may not understand how it all works but I believe that to be so. My belief is a physical thing It’s easier to abstract it because it would take too darned long to write out all of the biological/social processes required to be entirely accurate, so to me, abstraction to a “pure realm of ideas” is just a matter of speed of communication.
I don’t know if there is a collective consciousness or not. I wouldn’t be surprised if we are a single organism that has existed for millions of years that covers the planet earth like a Slime mold across time, but I’m not ready to say that for sure just yet
I don’t think cognition is required for a concept to exist – I have an example I’ll give in a moment.. I think the idea of the “idea” is a physical process of conceptualization but abstracted for convenience and acts as a complicated analogy for what would ultimately be sensory in nature, or related to the inner machinery already present in the brain.