This covers two of my big problems with most "but make them alien" requests.
The vast majority of fantasy races see more or less the same spectrum of light that humans do, and while low-light vision is helpful, it only works out to about 60', so it's not exactly They feel comfortable in the same range of temperatures, they eat more or less the same foods, they have more or less equivalent palates (possibly being slightly more or slightly less sensitive, but what one finds spicy, most will also recognize as spicy), they spend loosely equivalent amounts of time sleeping. They're bilaterally-symmetrical, bipedal, plantigrade, mammalian, viviparous, capable of sweating, have five digits per hand/foot, etc., etc.
The one thing that actually makes some races genuinely pretty alien compared to humans is never actually given meaningful attention in D&D, and that difference is lifespan. Lifespan differences should make dwarves and elves very different from orcs, humans, dragonborn, etc. Instead....it's basically written off as "yeah they just take life at a slower pace but are otherwise the same."
But because those two races have some of the longest history in D&D, we're never actually going to get truly alien elves and dwarves. This makes complaints that anything new (dragonborn are the commonly-cited example) is reducing D&D to "rubber forehead aliens" deeply frustrating, because it already was! It's just that the two most egregious rubber forehead aliens get grandfathered in, but anything with the temerity to not be included in Tolkien's work must jump through a dozen hoops just to get rejected anyway for not being alien enough.
Real, outright xenofiction levels of portrayal would not an interesting RPG make.