I agree! We could be working on projects to improve the ecosystem of Earth, exploring the oceans, and exploring space. We have the bandwidth to do so. We just need more people who are motivated to do it and make a change.

That point is not in dispute. What I think would be better than spending the amount of effort and time to get to Mars, which I am unconvinced solves our long term problems in any way, would be to better pool those resources into solving the root issues that afflict humanity like aging, pathogens, degenerative diseases, the need for so much food, the pollution we create, and the resources we consume. Working towards changing the human into something better, whether it be through improving our own hardware(biology) or bringing us into a digital realm(cognition). If we don't do that sooner, we're more likely to continue to suffer from the problems we are inevitably facing and end up, as I said earlier, turning planets into mere storage compartments. We can certainly do multiple things at once, but resources are not infinite, and I don't think all avenues of spending those resources make sense.

Just about all human effort is directed towards things which aren't curing disease and downloading our brains to a computer. So it's not SpaceX to complain about. It's the corner store and the hairdresser down the road. Collectively they're all wasting far more effort on far more useless activities than SpaceX ever will.

More directly to your point - Mars solves the risk to our species of a comet strike. Musk mentioned extinction events in the video. They've happened before and will happen again. All the health and cognitive improvement in the world won't save us from that.