Bagpuss
Legend
Racial modifiers should only be for the player characters or important NPCs.
Weird I would be more tempted to go the opposite way. Fixed racial modifiers for typical average NPCs, and flexible ones for PCs or key NPCs who are by definition "exceptional" characters.
An entire race should never automatically get some plus or minus. That goes down the road of racist comparisons.
You understand race in D&D is not the same thing as what people use to describe "race" in the real world. Races in D&D are completely different species. Are you telling me the average field mouse is as strong as the average elephant?
The average person in a human town or in an orc town or an elf town should always default to having the same average abilities, which in 5E is 10-11. If a member of one of these races has a stat or stats different from the average, there should be a story or explanation for it.
Yes one species has significantly more muscle mass than the other. One species brain developed differently than another's, etc.