[Question] What novel, actionable advice does longtermism offer?

I have not researched longtermism deeply. However, what I have found out so far leaves me puzzled and skeptical. As I currently see it, you can divide what longtermism cares about into two categories:

1) Existential risk.

2) Common sense long-term priorities, such as:

  • economic growth

  • environmentalism

  • scientific and technological progress

  • social and moral progress

Existential risk isn’t a new idea (relative to longtermism) and economic growth, environmentalism, and societal progress aren’t new ideas either. Suppose I already care a lot about low-probability existential catastrophes and I already buy into common sense ideas about sustainability, growth, and progress. Does longtermism have anything new to tell me?