Defaults definitely matter (that's why Google pays Apple for default status), but legally what matters is if the contracts are exclusive. That's what this fight over the "power of defaults" is about. Microsoft and the government argue that they are exclusive because, while consumers can change the default, they don't in practice.

But the fact that consumers clearly know how to change the default on Edge fatally undercuts that argument. And if the contracts with Apple aren't exclusive, Google can't be liable for them under the antitrust laws.