Musk isn't limited to Twitter. ;) There are many good long-form videos (interviews, lectures, Q&As) on youtube. An oldie but a goodie: https://www.youtube.com/watch?v=uegOUmgKB4E
Wait But Why is certainly popular, but it's not good at delimiting where Elon Musk's words end and Tim Urban's speculation begins. I also found oversimplifications and even downright inaccuracies. I'd recommend treating it as an introduction to Elon Musk's thinking, not as some final revelation.
If you think Musk doesn't care about Earth problems, check this out: https://www.youtube.com/watch?v=xKCuDxpccYM
Wait But Why is certainly popular, but it's not good at delimiting where Elon Musk's words end and Tim Urban's speculation begins. I also found oversimplifications and even downright inaccuracies. I'd recommend treating it as an introduction to Elon Musk's thinking, not as some final revelation.