Maybe! Switching search engines is also very easy, and the top story on the front page is someone no longer using Google, but we know in practice almost nobody does that. As technologists we're much more likely to switch and know people who would switch.

Same strategy as for search. Gemini is going be shoveled down the mouth of users and they just won't change the default.

On iOS with the Apple agreement, and on Android (though the question of hardware remains when considering beyond Pixel phones).