Many of the evil races (another word that is very charged and means something else in D&D) are the way they are because of the outside influence of their gods. It is not generic but religious and societal factors that make the average specimen of the different monsters most likely to be a certain alignment.
At some point around either the release of Mordenkaninen's Tome of Foes or Eberron: Rising From the Last War (I forget which) it was stated in a video WotC put out that the races of Eberron are unlike how they are depicted on many other worlds because they are protected from the influence of the creator gods. They used dwarves as an example, stating that even Moradin supernaturally influences dwarves to act in accordance for his design for their lives. This shifts the framing from "this kind of creature is biologically evil" to "gods supernaturally influence their creations to act in accordance to their will for them".
Explorer's Guide to Wildemount tries to have its cake and eat it, too. The book states that drow, orcs, and yuan-ti were manipulated and used by their evil gods, but that after a certain event this supernatural influence faded. The drow of Wildemount have rejected Lolth (and apparently in Tal'Dorei Reborn are looking to team up with the elves of Tal'Dorei to "save" those drow who still follow Lolth from her influence). Orc priests of Gruumsh teach that orcs are inherently vicious and can never peacefully coexist with other peoples...but this actually isn't true and just Gruumshite propaganda.
However, goblins ARE, for whatever reason, still vulnerable to being influenced by their creator god Bane from birth to play the role of goblin, hobgoblin, or bugbear, as he intended for them, and can only escape it via magical means to remove his Curse of Strife (such as Remove Curse or the proximity of a Luxon beacon) or an extraordinary act of mercy when the goblin expects death. Perhaps this is because Bane is the god of tyranny, and his tyranny includes mind control? One group of goblinkin is mentioned that searches for fellow goblinkin to save from Bane's curse.
Yuan-ti are still mostly evil followers of Zehir who mostly live in an isolationist city-state, with the one good group of yuan-ti who oppose their creator suffering under a curse of sickness inflicted by him. They don't seem to be supernaturally brainwashed from birth like goblinkin are said to be, but living in a theocratic city-state probably makes that unnecessary.
So, effectively, the situation has shifted from "gods made these creatures inherently evil" to "evil gods supernaturally influence their creations", which sets up the possibility of PCs thinking "okay, if they aren't inherently evil it would be bad to kill them...so let's convince them their religion and god is evil so that they reject it and maybe start worshiping the gods we worship instead". Wildemount and Tal'Dorei Reborn both feature a group of individuals (goblinkin in the former, drow in the latter) who wish to convert their kin away from their gods. Which of course has parallels to real world situations where visiting missionaries try to convert people away from their "evil" gods, with the caveat that in the fiction these gods (Bane, Gruumsh, Lolth, Zehir) actually are evil.