Out of the 4 major browsers, 2 major browser vendors have support for the base stuff, 1 has it behind a flag being tested ready to be turned on, and 1 doesn't have any support yet...
It's unflagged in firefox nightlies. Edge needs to get with the picture but really they are the only one out at this point. The polyfils, while not ideal, work great and shouldn't be needed much longer. The mobile story here is actually quite strong, since all major mobile platforms have full support for it.
