We need to do a lot of things. But I don't need to elucidate on that point because according to your second paragraph you already understand that.

There's a lot that needs to change about the world. It'll happen incrementally until it reaches critical mass to happen all at once. But breaking it up into separate domains and acting like we need to focus on one thing at a time is nonsense.

There are enough people in the world to divide things up according to expertise. Some people can work on reforming healthcare while others reform agriculture while others reform energy while others reform housing while others reform education while others reform whatever other sectors they're involved with. There's no need to put some sectors on hold until other sectors improve. That'll just create a bottleneck and stifle progress.

Some of these issues are interdependent anyway, and require simultaneous cross-sector reforms. For instance housing and agriculture reform depend on energy reform. Healthcare reforms depends on education reform. Honestly, it all depends on education reform. And possibly even electoral reform, which in turn also depends on education reform. But you can't reform education without also reforming housing, energy, agriculture, elections, etc.

The good news is we don't need to do things one at a time. To use a computer analogy, we're capable of parallel processing. Each sector is like a separate processor core, and each expert in a sector is like a separate thread in that core. We can do multi-threading, it's fine.