> The one you choose to run can be better than the current one you are forced to use and thus your attack surface has decreased because you are not using the worse ones.

you seem to think that webkit is the worse one here and that having for example a blink based or gecko based browser would means that these kind of bugs don’t happen.

that is unfortunately just wishful thinking. just read through the release notes of Chrome and Firefox and you will see that they all fix security bugs for every release.

all browser engines are of extremely high quality. but they also all keep having regular and security bugs.