Parmandur
Book-Friend, he/him
Have you looked at the DMG table referenced here.
There is nothing unclear about it.
To create an Aaracocra Commoner (or Spy, or Bandit Captain...) you modify that NPC statblock by adding +2 Dex, +2 Wis, you give it Dive Attack, talon attack action, reduce speed to 20 ft but give it Fly 50 ft, and let it speak Auran.
To learn the actual details (for instance, "what is dive attack") you simply go to the Aaracocra monster stat block and read
Dive Attack. If the aarakocra is flying and dives at least 30 feet
straight toward a target and then hits it with a melee weapon
attack, the attack deals an extra 3 (1d6) damage to the target.
Obviously this involves a fair bit off cross-referencing, but since you only need to do it once (per character you create) it does provide a LOT of player character race options in a very small space indeed.
Yeah, exactly; and for raves that don't have much unusual going on, or need much in the way of culture explanation, it is plenty.