Defaulting the search to Google in Safari in no way impairs the users ability to choose an alternative search engine. Apple have always left the search setting changeable, for a long time have allowed 3rd party browsers and have allowed other browsers to be the default system browser. This is hardly a monopoly and it’s no secret that Google is paying them gobs of money to be the default. It’s a separate issue from their appstore business entirely where security and privacy are legitimate arguments for the control they exert on that business.