I agree, but I will say that if your site doesn't rely on newer CSS features, IE11 is still surprisingly easy to deal with. A whole lot of cutting-edge JavaScr

I agree, but I will say that if your site doesn't rely on newer CSS features, IE11 is still surprisingly easy to deal with. A whole lot of cutting-edge JavaScript can be polyfilled/transformed to work on IE11 (automatically in most cases, with something like Babel), and the module/nomodule pattern can stop that polluting your bundles for modern browsers. It also has decent flexbox support (just a few oddities easily worked around IIRC), although its grid implementation is incomplete and uses an older version of the spec that in most cases just isn't worth the effort.