> Closed source = vaporware

Then why has Firefox been the 'shit' browser for the better part of a decade now?

Best battery life (usually by a 2-4h difference!) -> use Edge/Safari

Best stability -> use Chrome

Best performance -> use Blink-based browser

Most extensions -> use Firefox (Chrome has 90% of the FF extensions available though)

Hell, Firefox still doesn't have e10s fully working, so one tab takes down the entire browser. Slow sites lock up the UI. Scrolling sometimes still isn't smooth. Plus, Firefox is ugly, especially on mobile. and whilst its admirable they still prop up Gecko, its a substandard rendering engine compared to Webkit, Blink or Trident/EdgeHMTL.