We had so few IE8 specific hacks. I don't think it really made a large impact honestly.
Re:Bootstrap 4 alpha
by scott_karana on Wednesday August 19, 2015 @02:01PM
(#10087287)
Similarly, jQuery 2 shrunk 12% because of cutting out IE≤8 hacks: http://blog.jquery.com/2013/04/18/jquery-2-0-released/
This sure contributed to reducing the size.