"Declining job market participation is troubling to some economists because a robust labor force is important to overall economic growth. "

It is more likely that those economists see that the balance of power between labor and capital is shifting and Covid-19 is making it difficult for capital to do anything about it. This is the motivation behind McConnell's refusal to provide any substantial aid to the working class. Corporate profits and the way Wall St maintained its growth through the pandemic depend upon a subservient and relatively cheap labor force desperate for whatever income they can procure.