My understanding is it sort of relates to a simulated acoustical physical space the music is intended to seem as if it is reverberating throughout
Is it correlated with the intimacy or closeness of the music, what else does it evoke? What is its relationship with artificiality and nature respectively?
What is its evolutionary purpose in terms of why we can parse and interpret it?
Just spitballing here. First and foremost on the listening side, if used subtly, reverb is a great tool to make the music feel more organic. Theres an uncanny quality to very dry sounds, since we are subconsciously used to some level of reverb. Then, on the playing side of things, reverb is a great way to hide mistakes, muffled noted, and every other happy little accidents.