And if a critical amount of people decided to try luck working on asteroids, it might mean that they didn't had a comfortable way of life down here at the start of the process, and probably by the end of it too.
The people of Earth live relatively cushy lives at the expense of the belters. The UN and corporations extract resources from the belt, they overthrow democratically elected leaders to prop up corrupt puppet leaders to do Earth's bidding. All the while, the belters see little of the riches that they're force to extract. Also, unfortunately for the poor of Earth, that wealth also doesn't trickle down to them.
It is a pretty accurate analogy of the current state of affairs of Earth today, but the divide is between the Global North and the Global South.
The people of Global North live relatively cushy lives at the expense of the belters. The governments and corporations of the Global North extract resources from the belt, they overthrow democratically elected leaders to prop up corrupt puppet leaders to do Global North's bidding. All the while, the working class of the Global South see little of the riches that they're force to extract. Also, unfortunately for the poor of Global North, that wealth also doesn't trickle down to them.
The Earth of The Expanse is a warning, not an aspiration.
and if air quality worsens now that the EPA decided climate change isn't real, it paves the way for more entrepreneurs of this kind ("see? economic growth!!")
[0] https://www.cbc.ca/news/canada/calgary/alberta-vitality-air-...
This is similar to when people call The Sprawl a dystopia: conditions in it are far better then what most people live in today.