It depends. It's sometimes possible to increase profits without harming others, but _maximizing_ profits will eventually cause harm (by definition, it's optimizing for profit at the expense of other factors). Competing on the basis of profit in a field of competitors will naturally push you to maximize profit, i.e. to maximize efficiency and externalities.

That's what corporations are — large, complex machines under steady selective pressure to maximize efficiency and externalities. If you're lucky, they will go the efficiency route. But if it's easier, or they're already pretty efficient, they will tend to maximize negative externalities instead.

So guardrails are needed. Reasonable people disagree about where the guardrails should be. One thing that is hard to dispute, though, is that seeking profit, and continuing to focus your attention on increasing profit, will bias your thinking about where the guardrails should be.