Goblins mostly aren't that smart to be evil in same way as humans/elves/drow. They also have natural tendency towards evil, something that the races mentioned before lack.
What you call "evil" may not be considered "evil" by the character itself. For example, you say that goblins are too stupid, but this does not prevent them from being cruel, just because it is normal for them. They don't think they're doing anything wrong. I'm sure it works for drow too. The definition of evil or good actions comes from "morality", according to moral principles, some actions are considered evil, but the fact is that the concept of morality and justice in each society is different. So what you would consider a "tragic situation" would be something for drow to laugh about.
It is surprising to me that Minthara's fate as a cleric in drow society could be tragic. As far as I know, cleric of Lolth occupy high positions in their hierarchy. She should have been respected.
lore refer to almost all of them going insane
Almost all of them? Can I ask you for a source? I want to read it.
Yes, no problem.https://forgottenrealms.fandom.com/wiki/Drow
Unlike inherently evil creatures like orcs, the evil of the drow wasn't of inherent nature: They enforced the Way of Lolth, leading to a race of emotionally stunted people, with a tenuous grasp on sanity and scarred mentalities, among which relatively undamaged minds were considered abnormal. However, as mentioned above, the drow had no innate drive towards evil and their morality was colored by the society they lived in.
The difference though, is that goblins even if exposed to good behavior towards them, may still not get it and will not change. It's literally not possible for them to understand.
Drow, if removed from their society and treated well, will in majority of cases become better people.
The very ract that cult of Lolth is forcibly enforced, tells you that it's not uncommon for drow to have doubts about it.
I do not think that fearing about your life every day as a drow, would be trurly enjoyable for anyone but really crazy people. Fear is always negative emotion, which can turn life into suffering. So is being forced to hide all of your emotions and de facto being alone, since noone can be trusted.
Her life, even as a cleric of Lolth is still tragic, because if she would be born as a noble elf on surface, certainly there would be less negative aspects than here, not to mention very important thing:
With greater power, comes greater responsibility.
As a priest of Lolth and a member of powerful noble family she is even more exposed to all the infighting, betrayals and struggle for power. That includes trying to survive among people who want to get rid of her.