Imagine if Microsoft would prohibit you from using Google search on Microsoft devices and force you to use Bing and anyone would justify this on the basis that Bing is unpopular.
Microsoft is currently using Windows as a platform to try and push users into Edge instead of Chrome. Do any of us have a problem calling that anticompetitive?
Because it is anticompetitive, it doesn't matter that Edge has a trailing markeshare behind other browsers, it's still user-hostile anticompetitive behavior.
It’s about locking competitors out via owning the leading market in other parts of the dependant ecosystem. If MS didn’t lead the market in desktop operating systems then it wouldn’t matter what search engine they defaulted too.
Mind you people on Apple systems can still use Safari, people on Windows will always be able to use Edge etc, but there is no coherent argument for not putting more equal choices in front of a user across systems. All these companies make general purpose computing devices, there is no downside for the consumer in having control over them.
To let a company be anti-competitive and lock down a platform, so people have to use their proprietary software rather than being able to run a real version of Firefox or Chrome is completely backwards.
If you have a 10% market share and you use that 10% market share to expand into other markets then you’re increasing competition.
But if you have a 90% market share, then you’re not simply just expanding into other markets, you’re eliminating competition from those markets.
Imaging you have a birthday cake but you said only your best friend could eat it. That would be unfair to the other guests. But if everyone turned up with their own cakes and offers up slices to other people, it then means everyone gets cake and it doesn’t matter as much who you give your cake too.