Google isn't the only company shipping a browser. They may be the highest by market share, but I think that Firefox, Brave, and numerous others would like to be able to compete on the merits on iOS.
Firefox is barely surviving and is using funds from Google. If Google stop those funds, its gone.
Webkit is from Apple and if you look on my apple it is only alternative till today. If IOS allow other browser then you should know web will be in hands of Google.
Google can do whatever they like. And web being in hands of Google is dangerous.
They cannot.