Also latest Chrome.

Few companies could get away with this UX, but Apple is one of them.

HLS is an open standard (and a very simple one); Firefox and Chrome have just avoided implementing it for some reason.

From my reading, it appears off of any standards track it might have had -- it remains something Apple made up and can change however they like.

Which would be a great reason for not implementing it in an open browser.

Requirements: Live streaming uses Apple’s HTTP Live Streaming (HLS) technology. HLS requires an iPhone, iPad, or iPod touch with Safari on iOS 7.0 or later, a Mac with Safari 6.0.5 or later on OS X v10.8.5 or later, or a PC with Microsoft Edge on Windows 10. Streaming via Apple TV requires an Apple TV (2nd or 3rd generation) with software 6.2 or later or an Apple TV (4th generation).