That way, you get to have your Halfling with +2/+1 however you like, but only because your whole character builds up to that combination.
Which is a better way to do it than 5e handled it to be sure, but given that we're discussing 5e we kind of have to go with the rule sets they presented.
Which includes Tasha's, since that is an official book put out by Wizards introducing an optional way to build your character.
Personally when 6e comes around I am kind of hoping they'll abandon the racial ASIs entirely and put more focus on designing the racial abilities to be unique, interesting, and at least close to all being compelling choices regardless of your class.
Especially for poor dragonborn who's racial abilities are really underwhelming in 5e.
