Yeah, I was presenting two opposite ends of the spectrum. But the Prime Directive is often interpreted to prohibit acting in both of those cases. The question is where is the line?

What about a civilization that has a unique fuel source and they created a massively progressive civilization based on it. But when their technology progressed they suddenly realized that fuel source had subtly poisoned their world and they were doomed to all die? They couldn't have known before their tech advanced and their tech would never have gotten that far without that fuel source bolstering their progress.

Do you intervene?

We can create lots of hypotheticals that do this same thing and honestly a good % of Star Trek episodes are just this question in detail.