That means no updates and, most important, no security patches. No one should be using these older browsers. If you're on something like Windows Vista, which can't handle IE11, switch to Chrome, and be done with it.
It's time for developers to strip out code designed to support anything before IE11 - leaving it in there is just "enabling behavior."
(The same is true for most of the browser-specific CSS, aimed at older versions of Chrome, Firefox, and Safari: -moz-something, -webkit-something, and so on. These browsers are self-updating. Any user who has disabled the updates is just asking for problems. And why load up your CSS with a bunch of stuff that 0.002% of your visitors need?)