The lore says humans are the supreme wizard race, with the literal god of magic having been one, under the old rules a human wizard can never be as good as a gnome.
You keep saying this. Can you provide a source for humans being "the supreme wizard race" (namely compared to gnomes)? If the entirety of your evidence comes from there being more named archwizard humans than archwizard gnomes in 5e material, then there's another explanation: humans are the most common race, and due to the Bell Curve there will be more humans with Int>15 than other races. Actually there's a second reason too: WotC focuses more on humans than other races.
Let's take your claim as true. Humans are the supreme wizard race. Doesn't that mean that humans should actually have *larger* ASIs in Intelligence than gnomes to reflect this? Or some other trait that gives them a stronger innate connection with or aptitude to understand the weave?
