Is it still necessary to use sizzejs?

Is it still necessary to use sizzejs?

I'm using a custom jQuery build through this site: http://projects.jga.me/jquery-builder/ .
JQuery build: without deprecated, without event alias, and without sizzlejs.

Building without Sizzlejs really reducing the size of the file. And selectors still work fine.
For IE, I just supports at least version 10. The question is, what is the advantage of using Sizzlejs when i just support the latest modern browser? And whether the benefits without using Sizzlejs?