They produce top 4 numbers of adventurers. In a game of adventurers, that's plenty activity. There's no requirement for races to be industrious like ants.
And that makes no sense.
Why would halflings ever leave their ideal safe homes?
Why don't retired halfling adventurers encourage halfling to help the poor races outside who actually have...gasp.. problems?
This mentality doesn't make them human. It makes them alien. Even the country bumpkins who adore rural life enlist in war to defend the nation and donate to war efforts.
How can an iconic race who is supposed to be relatable be so passive. 5e halflings are neither active nor reactive. They are just there.
I would imagine halfling adventurers are similar. They only quest because the human, dwarf, and elf wish to go and the halfling wants to be with their friends. I can't see halflings taking initiative as their whole motive is sitting around and having fun with friends.