Yeah. I would ditch the halfling racials and just make them these.
1. Vanish into the Background: Proficiency and Expertise with Stealth.
2. Mental Fortitude: Advantage on Int, Wis and Cha saves.
I think that bravery got added to them, because the hobbits of the Fellowship were very brave, but that doesn't have to be racial. I'm not sure where lucky came from. The stout resilience I'd just fold into their racial ASI and go with +2 dex, +1 con. Halfling nimbleness doesn't really need to be a thing.
As near as I can tell, it all started with 3e giving them a +1 luck bonus on all saves. This is where the brave thing started too. Oh and Nimble, with their bonuses on Jump and Climb checks.
Before then, they had the "shorty bonus" to saves based on Constitution, similar to Dwarves and Gnomes.
3e seemed to have a mandate to "de-Tolkien-ify" Halflings, so they did this to differentiate from the AD&D Halflings.
4e decided to go in a different direction, and made Luckiness their big trait- it started with being able to force a reroll on a successful attack made against them once per encounter, and had Feats that could boost this ability (my favorite was the one for Martial characters, where the reroll had a -5 penalty and could not crit, even if a 20 was rolled).
It's at this point that Nimbleness was weakened to being merely a bonus to AC against opportunity attacks, and Halflings lost any bonuses to Stealth beyond Dexterity.
5e gave us this disconnect where the same basic traits are kept (Halflings are nimble, lucky, and brave), but the lore hearkens back to AD&D, where Halflings are stealthy and reserved, not adventurous.
"We are plain quiet folk and have no use for adventures. Nasty disturbing uncomfortable things! Make you late for dinner!” -Bilbo Baggins