This sums up a lot of what a lot of people are saying, that more ASIs hit a point of diminished returns, that getting a +1 to your tertiary ability is less important than a +1 to your prime ability. We're specifically talking about the half-elf being more powerful than the human for charisma classes (though I think they might even be competative without it). So, what are the primary, secondary, and tertiary scores for each of the Charisma classes?
Bard, Sorcerer, and Warlock all* want Cha, Con, Dex. Their +1's will be beneficial all around. They can do really well with their 15, 14, 13 jump up to 16, 16, 14. (*All is hyperbolic, I'm sure there's some builds that would want maybe a higher Str or something).
Paladins will likely want Str, Cha, Con, so that same 16, 16, 14 set up is great for them. Even my finesse Paladin is happy with Dex 16, Con 14, Cha 16 (or maybe switch the Con and Cha).
It's almost as if people also forget that Dex and Con are a little OP and nearly all of the Charisma classes are going to be wanting them to some degree.
Now, the base human's +1 to all 6 stats definitely gets into the territory of that 4th, 5th, and 6th +1 not being worth that much, and that's why I haven't really seen it picked. That first level feat is nice.