It wouldn't cost them money, they would just make slightly less money per year. Which is just me being pedantic, but it matters in these contexts.

Like, Bezos could have been the most loved billionaire on the entire earth, just through treating his workers slighty better and some minor philanthropy on the side, but no, he had to squeeze every fuckin penny out of everything.

That's a bit pedantic. It currently is an issue and Amazon isn't going to change anytime soon.