Why specifically Dwarf ?
We also have no Half-Orc, Gnome, Halfling, or Dragonborn.
Good people have no Drow.
By the way, there was no Dwarf companion in BG1 or BG2 either, unless you would accept evil characters[1]. And Dwarf protagonists wouldnt get any romance at all in original BG2.
But if you accept these hired companions, you can get almost all races, except Dragonborn:
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Eldra Luthrinn - Gold Dwarf - Background: Outlander [Athletics (Str), Survival (Wis)]
Barbarian - Str 17, Dex 13, Con 15, Int 8, Wis 12, Cha 10
"Eldra Luthrinn, slayer of people, monsters, and cups of sweet pear tea, was shown a watery grave when hunting Absolutists in the valleys of the Chionthar."
Brinna Brightsong - Lightfoot Halfling - Background: Entertainer [Acrobatics (Dex), Performance (Cha)]
Bard - Str 8, Dex 15, Con 13, Int 12, Wis 10, Cha 17
"Brinna Brightsong's bawdy crooning was silenced by an Absolute bloodbutcher after a controversial performance in a Triel tavern."
Zenith Feur'sel - High Elf - Background: Acoylte [Insight (Wis), Religion (Int)]
Cleric - Str 11, Dex 14, Con 13, Int 8, Wis 17, Cha 12
"Zenith, once an optimistic Evereskan Graycloak, journeyed to Faerûn in search of a new sunrise. An Absolute warband proved his dour father right: Zenith was doomed!"
Danton - Mephistopheles Tiefling - Background: Folk Hero [Animal Handling (Wis), Survival (Wis)]
Druid - Str 10, Dex 14, Con 14, Int 8, Wis 17, Cha 12
"Danton was a refined druid and rearer of peacocks - until he thought transforming into one would help him escape Absolutist marauders. He was wrong."
Varanna Sunblossom - Wood Half-Elf - Background: Soldier [Athletics (Str), Intimidation (Cha)]
Fighter - Str 17, Dex 13, Con 15, Int 10, Wis 12, Cha 8
"Once a battle-worn veteran fighting for the Absolute, Varanna learnt that loyalty to the would-be god did not protect you from the murderous whims of jealous generals."
Sina'zith - Githyanki - Background:Outlander [Athletics (Str), Survival (Wis)]
Monk - Str 12, Dex 17, Con 14, Int 8, Wis 14, Cha 10
"Sina'zith's monastic preferences marked her a misfit among her kin - as did the illithid tadpole an Absolutist forced in her mind. For this, the githyanki slew her as an aberration."
Kerz - Half-Orc - Background: Noble [History (Int), Persuasion (Cha)]
Paladin - Str 17, Dex 12, Con 13, Int 8, Wis 10, Cha 15
"Kerz lived many years as a paladin and mercenary, years which took a hard toll on them. Befriending a group of pleasant ogres, they laid down their weapon and taught a rudimentary etiquette class, before the ogres were attacked one night, and Kerz once more took up their steel."
Ver'yll Wenkiir - Lolth-Sworn Drow - Background: Criminal [Deception (Cha), Stealth (Dex)]
Ranger - Str 12, Dex 17, Con 13, Int 8, Wis 15, Cha 10
"Ver'yll spent his twilights scribbling odes to leafy canopies, bushels, and the merits of the noble hedgehog. When he refused to join the Absolute, its forces tore his forest and body apart."
Maddala Deadeye - Human - Background: Urchin [Sleight of Hand (Dex), Stealth (Dex)]
Rogue - Str 8, Dex 17, Con 14, Int 13, Wis 13, Cha 10
"Madalla's blindness was cured by another True Soul passing through her village - so they could watch it being burnt to the ground around them. Such was the price of refusing the Absolute."
Fafner/Jacelyn?!? - High Half-Elf - Background: Guild Artisan [Insight (Wis), Persuasion (Cha)]
Sorcerer - Str 8, Dex 13, Con 15, Int 12, Wis 10, Cha 17
"Jacelyn was born a sorcerer, the seventh son of a seventh son. The agent of the Absolute that killed him knew this, and is rumored to have remarked, Probably should've left it at six."
Kree Derryck - Grey Dwarf (Duergar) - Background: Charlatan [Deception (Cha), Sleight of Hand (Dex)]
Warlock - Str 8, Dex 13, Con 14, Int 13, Wis 10, Cha 17
"Kree's penchant for killing folk with a mere whisper was prized in the Absolute's ranks, but the utter devotion to her patron was met with lethal disapproval."
Sir Fuzzalump - Rock Gnome - Background: Sage [Arcana (Int), History (Int)]
Wizard - Str 8, Dex 13, Con 15, Int 17, Wis 10, Cha 12
"Sir Fuzzalump was much mocked amongst his playful kind for his dour demeanour and single-minded devotion to the magical investigation of cave moss. He claims not to have giggled in over a decade, and has never frolicked."
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P.s.: [1] Ooops, wrong. There was a non-evil Fighter/Cleric in BG1. There was only one Dwarf in BG2 though, and he was chaotic evil.
Yeslick wants a word with you. Plus we had the gnomes Tiax, Jan Jansen and Quayle, Alora and Mazzy the halflings and the two evil dwarves. ANd hirelings are not the same as companions with story and dialogue