Every time people lament changes to the lore that amount to “not every member of species X is irredeemably evil” and claim the game is removing villains from it, I think how villains of so-caleld evil species fall into two cathegories: a) bland and boring and b)have something else, unrelated to their species going on for them, that makes them interesting.
It’s a lot more interesting to have a goblin that somehow managed overcome its evil nature if basically all other goblins are genuinely crooked and evil, than if they’re all “just another race” that’s misunderstood. Yes, most villains should probably be more interesting and nuanced than just being evil due to their race, but evil races/monsters aren’t a bad thing in a fantasy.
No one’s saying in the setting you’re playing in goblins can’t be evil as a default. Having it be a blanket truth for all settings is a bit constraining though. Goblins specifically in the DND world probably shouldn’t all be evil alignment because their history is… Complicated
I feel like the bigger reason to have evil races is to have a more or less ever present challenge and point of conflict. For instance, the underdark is horrible place to be, in large part due to the drow. Their presence and general alignment of evil makes the setting dangerous and interesting. Is this town safe? Have the drow been messing about assassinating local leaders? Should we help this group by liberating them from slavery from the drow?
It’s almost like their species is in of itself a character, with this species sized character being evil. Having an entire species be generally evil gives the world more scale than a single evil character would. But yes, an individual villain needs more than just their evil race to be interesting.