It's sad that a lot of sites decide to only optimize for Chromium/Blink and have horrible performance on anything else, or hold back features altogether.
Orion browser was posted here just recently and looks very neat which feels a bit snappier, though still a bit rough on extensions and doesn't support Safari extensions.
i use firefox as my main browser and ive found that a few sites which claim to not be compatible with ff work perfectly fine if i change my useragent to appear as chrome. it's really annoying and lazy to see how many people they're shutting out when they do this, vs just giving a warning that some features haven't been tested on browser x.
Mozilla can add a special case to make Firefox lie about its UA by default.
I started using Orion over the past few days. There are definitely some things I like, but even though it says it supports Chrome and Firefox extensions, the only one I care about is 1Password. It installed, but wouldn't run because Orion isn't verified in some way.
Also Blink based browsers have vastly more market share and generally if it works on Blink it will work on Firefox/Gecko, because unlike Safari/Webkit it doesn't live in the dark ages.
The only reason people don't outright ignore it is that it's the only engine that runs on iOS. This does often mean though people only test for it when doing mobile/responsive testing.
Apple either needs to really get off their ass and invest properly in Webkit or do something more drastic like adopt Blink (bad for us, browser monoculture but probably easiest option) or Gecko (good for us, unlikely to happen).
Safari is usually the last one to the party and often has the most lolwtfbbq bugs which to me was the essence of the IE6+ era.
Can you name a piece of software that does a better job about being open, transparent, & working in a more pro-social way?