This is a fundamental misunderstanding of what socialism and capitalism are. Simplified it’s who owns the means of production, that is basically the “capital” in the name “capitalism”, in socialism these means of production have a shared ownership. Now you can have a discussion of what that means, if state ownership counts or whatever but as long as individuals own the means of production it’s not socialism no matter how much you tax them(it would still be an improvement to tax them more it’s just not socialism)
Exactly, this argument is so weird, even if the assumption was true. “People are naturally greedy so we should have a system that allows them to do as much damage as possible”