> If it becomes illegal to pay to set a search engine as default
Just as the Microsoft antitrust case was never about whether it was legal to bundle a browser with an OS, but whether Microsoft's particular act of doing so was illegally leveraging a monopoly in the desktop OS market into other markets, the Google case isn't about whether its legal to pay to set a search engine as a default but whether by doing so Google was illegally protecting an existing search monopoly.
You can't just ignore the relevance of the market power premise of antitrust cases to which it is central and pretend they are about the actions without regard to market power.
If you make it illegal for Google to pay for it but legal for others to pay for it, then you basically enforced that all search engine defaults will not be the most popular one since they will all pay for that position while Google can't. Then the status quo is much better.
Just as the Microsoft antitrust case was never about whether it was legal to bundle a browser with an OS, but whether Microsoft's particular act of doing so was illegally leveraging a monopoly in the desktop OS market into other markets, the Google case isn't about whether its legal to pay to set a search engine as a default but whether by doing so Google was illegally protecting an existing search monopoly.
You can't just ignore the relevance of the market power premise of antitrust cases to which it is central and pretend they are about the actions without regard to market power.