You should consider that Forgotten Realms wasn't really the default setting before 5e.

In 4e it was Points of Laght/Dawn World/Netir Vale which was designed from bottom up to be easy to put in anything you want and it is credited for codifying on paper worldbuilding principles that are as wold as fantasy itsel (the poitns of light-style world). In 3e era it was Generic Setting, which was just Greyhawk without any words that would make them have to pay Gygax royalties. In TSR there was no default setting, they all just coexisted.

WotC turned Realms into a default setting by pretending any unique stuff doesn't exist or trying to make it "the default" - look at Gnolls. The "hyenas turned into half-demons from eating Yeenoghu's blood" thing could work for Realms (it's a new lore invented for this edition), but WotC just HAD to try to force it on ever other world they own, goig so far to retcon two Gnoll bodyguards in Sinsiter Secret of Saltmarsh into Hobgoblins, just to keep the illusion Realms have nothing unique going for it.