Disclaimer: I worked at Google for 6.5 years, although not on the Chrome team. I am currently independent. I also worked a little bit with Rob at IBM in 2001.
Rob O'Callahan has a good post explaining why you should use Firefox. I am sympathetic to this argument, but I can't bring myself to switch yet. I try periodically, and every time I end up bouncing off again. Alas, Firefox is currently inferior in specific ways that are cripplingly bad for my needs.
First, as a web developer:
- The developer tools are really janky.
- The profiles functionality is buried and has no in-browser UI. I need quick, simple profile management and switching when testing my apps. (Don't refer me to the add-on market; add-ons are a cesspool.)
Second, as someone who recommends tech to my family:
- Multi-process isolation and sandboxing have still not shipped.
- Firefox's updates are still not as timely as Chrome's. On my personal machines, I often find that I'm running an older version of Firefox weeks after a new version is released. In fact, just as I was writing this, I found that the machine I'm typing it on was still running 30.0, when 31.0 was released on July 22.
As a result, Firefox is plausibly the least secure major web browser shipping today. I can't recommend Firefox to my family until these things are fixed. I won't expose them to a high risk of exploitation, here and now, solely to protect them from a theoretical risk that they'll be harmed by the Chrome team's product choices in the future.
In addition to all of the above, I think Rob overstates the extent to which Google is (1) winning and (2) likely to use that position to harm users in the foreseeable future.
Obviously, I am biased w.r.t. (2), so I don't think it's productive for me to try to convince you of my point of view in this post. At any rate, Rob is better-informed than me about browser politics, not to mention much smarter than me, so I am willing to believe that he has good reasons for believing what he does.
However, w.r.t. (1):
- On desktop, Chrome doesn't even have majority market share. It is trending upwards, but it's a long, long climb from its present ~40% position to the 80-90% that Microsoft once had in desktop operating systems. And Google's competitors today are a lot more impressive than Microsoft's were in the 1990s. I don't think it's plausible that a large fraction of the web will build strictly for Chrome, or even Blink-based web browsers, anytime in the foreseeable future, unless all of Google's competitors fumble the ball mightily.
- On mobile, iOs isn't going away any time soon. And I would bet (a small amount of) money that forks of Android, from China and elsewhere, will reach rough market share parity with Google Android in the long run..
Today's giants always look more invulnerable than they really are. Apple looked unstoppable just a few years ago, Microsoft not that long before that. Facebook looked like it would become the identity layer for all human interaction; now it's just a boring and somewhat declassé social media site for middle aged people (plus a server farm for a few flashy acquisitions). Google may seem like a juggernaut, and to be fair I think it is much more competent on average than any of the three companies I just mentioned, but it's vulnerable in ways that aren't even obvious to us today and I'll be very surprised if we look back in 2024 and find that Google is dictating terms to the rest of the technology industry, in the old Microsoft (or new Apple) mold, rather than being merely one influential player among many.
 Incidentally, since Google has let the AOSP web browser languish, and restricted Google Chrome(TM) to its increasingly-tightly-constrained partners, making Firefox run amazingly well on non-Google Android — well enough that non-Google Android users almost universally either get Firefox shipped with their device or install it themselves — might be a more plausible path to getting large mobile market share globally than Firefox OS. (I do think Firefox OS is an important and worthwhile project as well.)