Yeah, thought about the same. Many software jobs are just bullshit. They pay super well, but the sense is nowhere there.

I'm super curious what will be the answers.

Let's say:

<impact> = <number of people> * <size of change in their life>

Now, sometimes it's easiest to work on local scale, especially as this often gives you instant and materialized feedback. I would search for some kind of foundation or open source community. They often have massive outreach.

Personally, I found that technology people (like Silicon Valley or investors) have technology fixation, e.g. they believe (like in god) that technology will solve all problems. The most real, broad problems in the world need a political will to make a change. In this context the question is: can you influence the politics to be good?