If a construction site was sending formerly qualified people away no longer able to work we would definitely investigate their practices. Tech deserves the same scrutiny.
corporations exist to make money, or maximize shareholder returns, depending on how you look at it. corporations don't exist to make people happy or solve the fundamental societal issues with capitalism. there's merit to discussing that as a separate topic, but in the context of "capitalism exists and you are operating a business within it", you want to fire low performers and replace them with high performers
A band of criminals has no protection over their enterprise. They all go to jail.
And why we have these conversations: to build consensus over these rules.
But it feels like your take is: "Guess all there is to do is just sit and feel righteous indignation while companies have their way with us, and the world crumbles around us."
You shouldn't think of all firing as a "mistaken hire". Sometimes you hire someone, and they work effectively for years, and then they kind of "check out" and don't do much work any more. It can be a good decision to hire someone, and then later a good decision to fire them.
It's also not a cost-cutting measure per se. Typically when you fire someone you get to replace the headcount with another hire or internal transfer. The point of firing people is to get rid of low performers and replace them with high performers.