Without the legal pressure, the status quo would have remained, websites would still be optimized for quirks in how Explorer renders HTML (unless the developers

Without the legal pressure, the status quo would have remained, websites would still be optimized for quirks in how Explorer renders HTML (unless the developers were passionate enough about openness to spend the extra effort to work correctly for all browsers), and there wouldn't have been much incentive to improve Gecko or Webkit because Microsoft could just introduce incompatibilities into its rendering that would cause compliant websites to break other renderers. In an imaginary world where Android doesn't exist and iOS dominates the mobile world in the same way that windows dominated the desktop, I would hope that authorities would constrain them to prevent a similar scenario from happening with mobile browsing and apps. At a certain level of market share, these things become equivalent to natural monopolies such as electric power utilities and fixed-line telecom where providers would be able to economically bar new market entrants and then abuse customers at their leisure unless regulated.