The Half Elf is one of the better races in 5E, but we still see more Humans in my game. Half Elves make great Bards, Sorcerers, and Warlocks, as well as descent Paladins, but not everyone wants to play those classes. In addition, since we use feats, getting a start on a your defining feat is the equivalent of +2 to your prime ability, since you don't need to get the feat at level 4. The base human does occasionally see play, since we roll ability scores, if someone gets 4+ odd ability scores (this personally drives me nuts, but whatever).