Chaosmancer
Legend
Good. Problem solved.
Eberron is just as official.
Buy books that have stuff you like, don't buy books that don't. Not difficult.
And how does a new player who picks up the PHB supposed to know Eberron has more interesting haflings that they need to go online to research? Because, I'll let you know, the Talenta Halflings are not well detailed either. IT is certainly different and interesting, but they aren't a focus point of the 5e book at all.
What if they like halflings, but don't like the Mourning or the Dragonmarks, and so they don't want Eberron, then what? Should they buy it anyways because we don't believe WoTC should make better generic hafling lore?
This is not a "we did it once in one side product, therefore our main product is fine" type of situation.