First, there are some good points here! But...
With STR +2 universal to
all orcs, but not all humans put a +1 in STR
and take a feat that also grants a +1 in STR.
So, overall, orcs are "just stronger" than Humans.
And, elves are more dexterous than Humans.
And so on...
It is also why a lot of table like capping ability scores at 18, but your racial modifier increases the cap. So, using this, orcs would have a max STR 20, while a human would be limited to 19 (if you put a ASI +1 from human into STR).
And to a lot of players, myself included, orcs
should be stronger than humans (overall, that is...

).