The Left opposes adding a question on citizenship to the 2020 census form. The answer lies in abolishing all questions except those that count total residents. But that won't happen because the census is used to justify a myriad of government programs.
There is a persistent myth that capitalism has destroyed what would have been a natural abundance and peace of mind. Yet nature does not generate abundance or peace. The characteristic mark of the "state of nature" is irreconcilable conflict.
In a relatively unhampered market, a declining population is not necessarily an economic problem. But in a system where retirees can loot younger workers through government pension systems, there is a real problem, indeed.
Reparations to heirs of slaves make sense so long as the actually guilty parties are the ones paying. Short of that, the policy being discussed has nothing to do with reparations. It's just a wealth redistribution scheme.