I believe MS didn’t get nail on integrating IE into Windows - at least in the US - they got nailed on threatening to increase Windows prices for OEMs (which will ruin them in the competitive OEM market) that bundled Netscape, i.e. abusing their Windows monopoly to harm a competitor.

WhatsApp, Signal, Facebook Messenger are all free to download on iOS - heck it’s offered for download at Apple’s expense; since it’s from their App Store servers.