Oh it's less a fixation and more an interest in scale of impact. There's a lot of people out there who talk a big game but when you look at the results, they're clearly underwhelming. Edit: or worse, they're self-serving publicity not designed at all to do good. The blood donor in this thread is a great example of oversized impact, but that's difficult to replicate. It does give good food for thought in terms of things to look for that could use more support.
The multidimensionality is why I didn't provide any opening suggestions; I didn't want to guide the answers. This was so that I might find some dimensions I had not previously considered, and I was curious about what metrics others use to measure "good" in the first place. Unfortunately Elon Musk as always proved to be a topic that generates more opinions.
Thanks for the support though. Honestly, there are a huge number of good choices already, more than I could ever dedicate enough to. I'm hopeful there are some gems out there that have potential to really offset some the vast quantity of suffering the world has to offer, this was just a small experiment in looking outside my own bubble of experience for them.