In order to compete and grow, sure, reinvestment is needed. But even within capitalism, when markets are saturated the lay offs only happen because of a desire for profit growth when faced with a ceiling and they just cannibalize their own company because of perverse incentives. Cooperatives often willingly just impose pay cuts and hour cuts across the board during lean times like a market saturation and then usually endure as a result without the brain drain with their workers still "employed" at the end of the tunnel. Even if new market growth never comes, coops would simply stabilize and become easier work if become fairly low paying work. Where as capitalists tend to sell off the husk of a barely functioning firm for one last quick buck just before its usually doomed to closure from being carved up and mismanaged by leadership that no longer gives a shit.
I'm a socialist but not a strict Marxist. Even if I agree with a lot of his work, in particular I think his analysis is correct about the unsustainable relationship between labor and capitalists because of exploitation for profit, alienation, lack of control over laborer's own work, etc. That said, I find meta-narratives (by any economist or philosopher) fairly wrong headed and verging on mystical and the level of rigidity towards market's functionality regardless of potential configuration (like say into a mutualistic market system of coops) similarly wrong-headed and "prophetic". I meet that level of certainty with skepticism.
I do think that eventually a mutualist market would probably become sort of meaningless eventually and turn into something else.
A desperate belief that they are impoverished because they need to compete with an ethnic out group and a belief that the out group is taking their shit, murdering them, and stealing/raping their women.
Even though its largely due to capitalism and technologically induced paranoia & loneliness.