Is there a way to deque the style with higher priority?

Your problem lies in detecting browsers. There is no way for server side languages like PHP to know which browser is used to render a page/website. This is all client side processes.

Someone “clever” invented ways to detect browsers and devices in PHP and claimed it worked. Yes, it does work, BUT not always. As I said, server side languages cannot detect browsers or devices, and conditionals like the ones you are using (and the circus clown wp_is_mobile()) relies on client side prosesses which is never reliable as it can be altered nd modified on client side.

You are unfortunately stuffed here. You have something that will work in some cases and will fail in other cases, and there is nothing you can do about that. You will need to live with that until the end of days as I cannot see any reliable way for server side languages to ever detect browsers or devices

EDIT

To remove the stylesheet completely, you will need to deregister and dequeue it

add_action( 'wp_enqueue_scripts', wpse_219467_remove_webkit, PHP_INT_MAX );
function wpse_219467_remove_webkit()
{
    wp_dequeue_style( 'webkit' );
    wp_deregister_style( 'webkit' );
}