The Forgotten Realms is, and has always been, a Renaissance Festival LARPing version of contemporary America/Canada, from the perspective of people living in one of the large urban conglomerations (Ed Greenwood's Toronto, WotC's Seattle). Although the campaign setting was originally conceived in the 1970s, and TSR began publishing Forgotten Realms products in 1987, Baldur's Gate 3 is merely reflecting real-world demographic change as of 2023.
This has been gone over a lot, but I don't think making whites rarer than niggers and demons was ever anyone's vision before the year 2005 or so.
The 1970s idea of diversity, whether in Seattle or Canada, was always about the same ratio you see on Star Trek:
One black, one Asian and the rest white or white-appearing Jews.
Modern demographics have changed, but white male humans are not a minority like they are in BG3.
What has changed is the
idea of Diversity, which now means as few whites (especially white males) as possible. It used to be about diversity of culture, variety as the spice of life, and often a criticism of colonialism and racism. But now, it's an explicitly anti-white ideology, and BG3 reflects that in its design choices.
You can't have the default character be a white male even though your in-game stats show that's the most popular character. That's not Diverse! Any degree of racial homogeneity in any location? Not for white humans. Only for other races, or the Tieflings.
On the plus side, Forgotten Realms is no longer a Renaissance fair. It's now completely different from anything remotely historic. It's an alien world with only the barest traces of reality or tradition, and usually those traces are just there to mock - like the gnome couple in the Underdark, whose main purpose is to show the male as an abusive asshole whom the stronk female has conquered and put on a leash.
If TSR's Forgotten Realms was a Renaissance fair, Wizard's Forgotten Realms is a Pride parade.