To be fair, the same is true for all of BG3's cast besides Lae'zel. (Karlach's being a Tiefling is only relevant in that it gives a reason why she could survive in Avernus and the burning heat of her Infernal Engine heart - Beyond that, she could be anything).
Heck, even the Emperor being an Illithid feels kind of phoned in, even if it makes it into story it doesn't have any real relevance to the character (Especially given his stance of not being interested in becoming human again, so it's not as if his transformation has given him something to overcome...). Like, they could have literally have kept him as your Guardian throughout the entire game and nothing would really change for his characterization (If anything it might have improved things because then the choice between Emperor and Orpheus would be less ridiculously one sided, because instead of being a decision between Mr Evily McEvilface and Mary Sue, one of the characters is just a plain old adventurer who helped you out instead of an evil mastermind manipulating you for their own purposes)
It's one of the disappointing aspects of BG3's writing.
Though, DOS2 was much better in that regard. Fane being an Eternal, The Red Prince being a Lizard, Beast being a Dwarf and Sebille being an Elf were much more integral to their characters and stories (Of course, Lohse and Ifan both being human was, as is typical, completely irrelevant)
So it's not as if Larian cannot write race relevancy into characters. They just opted not to for BG3 outside of Lae'zel.
There are some minor relevances to for example Wyll being human because Ravengard is already established as a noble house of humans and Halsin and Minthara provide some lore relevant interactions to their race, but they are generally so underdeveloped that it doesn't add much.
