You obviously do not use, nor rely on, extensions. Extensions for Chrome/Chromium pale in comparison to what extensions for Firefox can do.
Want tabs on the side? Good luck with Chrome. Good luck with alternate Webkit browsers with not enough marketshare to attract extensions.
You obviously haven't tried the new "Australis" version of Firefox. It's stupid and dumbed down and in a few months it will be your only choice unless you stay with an older version of Firefox forever...
The one thing that that has always made Firefox better than all the other browsers is the ability to do extensive customizing. But they are hard at work fixing that. The new "Australis" build removes an enormous amount of customizability and is nothing but one giant Fuck You to users.
Tabs On Top -- No thanks, I want my tabs below the URL bar, where God intended them to be. Well, Australis says Fuck You, you're getting Tabs On Top whether you like it or not. And just removing the menu item and burying the setting in about:config isn't good enough. Even if you go into about:config and change the setting, it does nothing. Don't like Tabs On Top? Australis says: Fuck You.
There are only 2 toolbars -- Menu bar and Bookmarks toolbar. No more Add-On Bar, which means the Status Bar Extension (among others) doesn't work because THERE'S NO FUCKING PLACE TO PUT IT. It's bad enough they removed a feature and forced people to rely on an extension, but now, Australis says: You want a Status Bar? Fuck You.
The Back and Forward buttons are now welded to the left side of the URL Bar and can't be moved. The Reload Button has been replaced with a swirly arrow that is welded to the far right side of the URL Bar and can't be moved. And the Stop Button is gone completely. Want to arrange your buttons the same way you've had for years? Australis says: Fuck you.
Want text labels with your buttons? Australis says: Fuck you.
I could go on and on but fuck it I give up. If I want a browser with a shitty UI that can't be changed I'll use Internet Explorer or Chrome.