I don't find it at all difficult to imagine that someone like Google or Apple would sunset ipv4 when it reaches single digit percentage. They know no ISP would

I don't find it at all difficult to imagine that someone like Google or Apple would sunset ipv4 when it reaches single digit percentage. They know no ISP would risk losing connectivity to them. For example Apple has already been requiring that appstore apps work in ipv6 only networks since 2016. They can just keep tightening such rules until ipv4 dies. It's naive to think that maintaining ipv4 (/dualstack) networks is (and will remain) cheap at large global scale like Google.