I disagreed with the Microsoft charges back then, and I disagree with the case against Google now. I hate both of them and I think they use monopolistic tactics, but making their own search engine or browser the default in their OS isn’t monopolistic, especially since you can easily change it.
The tactics that should be fought against are things like when Google used its size and money to offer free unlimited cloud photo storage. That put several cloud services out of business because they couldn’t compete with “free unlimited” storage. Then, when all the competition was gone, Google started charging for their service which was no longer unlimited.
When someone tries to compete with Google, Google either uses their power to put them out of business or buys them. That is totally monopolistic and what the government should be defending against.