I think you have rose colored glasses on about Netscape around the time that IE was given away for free. I remember an article that came out in the late 90s comparing how badly NS crashed on every platform that it ran on.

Why is it anti competitive for MS to give away IE for free but not anticompetitive for Google to give away Chrome and Android for free or Apple to give away IOS/MacOS for "free". Every tech company "commoditizes their complements". IBM supports free operative systems to sell hardware and services, Apple gives away IOS updates to sell hardware, Google gives everything away for free to sell ads, etc.

Is it also wrong for open source software to be free?

Yes.

Why? Also, that's not the view of the court within the EU antitrust case against MS.

For consumers this later lead to other great free browsers.

Yes.