But even without ASIs--fixed, floating, or nonexistent--elves are different from humans. They have very different game traits. They have different biological needs (at minimum: sleep versus trance), and their biology is going to mean that they process information differently (at minimum: darkvision versus no darkvision). And they are going to have very different mentalities, personalities, interests, and desires due to being raised in likely very different societies and being of likely very different ages.
The fact that PH humans get either +1 across the board or +1/+1 and PH elves get +2 Dex/+1 something else means next nothing other than the most dexterous 1st-level point-buy elf is going to be marginally more dexterous than the most dexterous 1st-level point-buy human.