Like what?

I think the only time I've ever had to use Chrome instead of Firefox was because of some USB device thing that worked inside Chrome. Otherwise everything just works in Firefox.

The sites my colleagues and I produce. They consider Chrome === Standard and everything else a deviation for which they may begrudgingly fix obvious bugs in once pressed. It's seldom that entire sites will break in other browsers, but instead they simply do not work in some ways like modals sometimes breaking, or XHR requests failing, or performance being bad.

It's frustrating.