Base humans are generalists, which by their nature won't have something specific that stands out. +1 to each stat and I think an extra skill is nice if you like not being terrible at anything. Not great at anything is a tradeoff that other races don't have though...
It can be good for certain builds, but in practice 2-3 of those +1s end up being meaningless for most characters, and with the Tasha's changes, every character can freely distribute +1/1/1 or +2/1, making it a wash in almost every case, including on Vumans who can pick up an additional +1 from the feat. Between that and only getting one floating skill proficiency when most heritages get a fixed or small list skill proficiency in addition to one or more standout features, base human is by far the weakest choice.
I think giving a feat, a skill and an expertise would be a good way to set them apart a little bit from the other heritages.
Of course it only applies to some builds, like anything else. A couple extra bonuses to avoid negatives on savings throws can be nice though, if the goal is to reduce weaknesses.
Honestly, every class should get at least one skill with expertise. Maybe pick one from their class list, like a Fighter with expertise in Athletics so a Bard isn't better than them at throwing goblins around. A Bard and Rogue would just have more.