In what way? If each character can just pick and choose their attributes and other abilities, how is physiology important?
Dragon breath, flight and other movement modes (climbing, swimming, tunnelling, etc.), darkvision (though this one is controversial) and other perception abilities, whether or not one needs to eat/sleep/breathe, inherent armor (e.g. tortle and warforged), telepathy/telekinesis and other innate psionic/magical abilities, water breathing, carrying capacity modifiers (e.g. powerful build)...
These things are physiological, and cannot be freely-chosen in 5e as it currently exists. You cannot, for example, have both dragon breath
and darkvision on a single character. You can of course mimic it with certain choices of initial feats (e.g. Custom Lineage with Magic Initiate feat to get
burning hands or
frost fingers or the like), but the "genuine article" as it were is specific to a race that doesn't get darkvision. Likewise not needing to eat/sleep/breathe cannot be had on the same race as one that has telepathy. That combination of physiological features doesn't exist in 5e.
If we're talking about a
hypothetical game where all possible traits can be mixed and matched with the right sacrifices or tweaks, then sure, physiology ceases to matter beyond thematic relevance. But that would also be a game fairly different from the game we currently have.
Wouldn't physiology influence culture at least a little bit? Cultures with dark vision may have very different attitudes about the night from those of us who are effectively blind in the dark.
sigh Again, I figured this was so blindingly obvious I didn't have to say it. Yes,
obviously, physiology can have SOME influence on culture. A race that has a tail will build chairs differently compared to a race that does not have a tail.
It
should have been painfully obvious from both all the discussions of this up to this point (which there have been MANY on this forum alone) and all the stuff we've heard from WotC that there's something more specific being said when one says, "Physiology differs from culture." That is, up to this point, we've had race (an allegedly physiological status) confer things like Medicine or History, which are purely academic skills that come from training, not something that can be hardwired into a being's physiology.
Like...are you really going to claim you GENUINELY thought I was saying, "Physiology has ABSOLUTELY ZERO influence on culture!!!" and not the much more reasonable, well-evidenced,
specifically discussed, "It's kind of uncomfortable to imply that fully mortal, humanoid people with a certain physiology are just
innately good at telling lies, purely because of their physiological differences."?