MS got hit kinda hard back in the 2000s right?

But since then most cases have been nothing more than slaps on the wrist? Have any major companies faced dire consequences for their anticompetitive practice.

So why would they stop using their market position in ways that benefit them and at worst result in minor fines or wrist slaps?

Are you sure they lost? If the CEOs had perfect crystal balls and knew that those particular business practices would result in the penalties that they got in their court cases, I bet they still would have done the same things.