Gammadoodler
Hero
On the one hand I can understand some small value in reminding players that there is more stuff in the game world than that which is mechanically relevant to their characters.Mostly that it encourages players to give some thought to these things, even if only during initial char-gen and once in a while thereafter. On a broader view, it makes them remember the mundane.
It also gives me-as-DM a handy price guide as a start point if-when the PCs scoop a bunch of this stuff during an adventure and want to sell it.
Rarely. However, that's not an argument for saying they shouldn't be listed in the rulebook, if only because they have to be listed somewhere where they'll be seen by all and where else would they go?
Players rarely if ever reference the species write-ups after initial char-gen but they're still in - and should be in - the rulebook.
On the other, I think that there is enough rules content in the PHB to absorb without the inclusion of a bunch of red herring items that do nothing but take up space in the book, on player's character sheets, and in the back of gms' brains.
I think the purpose you're describing could very easily be served by a green box somewhere indicating to players that all that other "stuff" exists, and your character would likely have some of it. Then save the details for the bits that explicitly impact play.