Gecko these days is pretty good, but that's only half of the story unfortunately. This is a web runtime with no successful product to power anymore. Firefox Desktop is still declining despite the Quantum work, and on Mobile Mozilla products are not registering on any chart.
Ironically, the only successfully growing Gecko-based product is KaiOS (see http://gs.statcounter.com/browser-market-share/mobile/india) but the current MoCo+MoFo leadership killed the upstream support a while ago to focus on Desktop. Maybe they will see the light...
Ironically, the only successfully growing Gecko-based product is KaiOS (see http://gs.statcounter.com/browser-market-share/mobile/india) but the current MoCo+MoFo leadership killed the upstream support a while ago to focus on Desktop. Maybe they will see the light...