Agreed that Mozilla's original mission has been accomplished in spades, but I wouldn't count Mozilla out of the browser race just yet.
Servo and Webrender[0] will completely shake up the browser landscape, and will allow web apps to match (maybe even surpass?) native mobile apps in terms of rendering performance. Unless Chrome, IE, and Safari can develop an answer to Servo and Webrender by the time those technologies are ready for prime time, I wouldn't be surprised to see "Best viewed in Firefox" badges start popping up everywhere.
Servo and Webrender[0] will completely shake up the browser landscape, and will allow web apps to match (maybe even surpass?) native mobile apps in terms of rendering performance. Unless Chrome, IE, and Safari can develop an answer to Servo and Webrender by the time those technologies are ready for prime time, I wouldn't be surprised to see "Best viewed in Firefox" badges start popping up everywhere.
[0]
https://github.com/servo/webrender/wiki
https://air.mozilla.org/bay-area-rust-meetup-february-2016/