> But let's not forget that Opera browser earned its reputation for being blazing fast, its tiny size and its low memory consumption on the desktop platforms long before it became a popular browser on the mobile platform.
Just about all of the major browsers earned their reputation for being blazing fast, tiny, and using little memory. And those attributes are well-deserved at their launches. Then real-world pressures kick in -- it turns out that although people love small and fast, that doesn't do them much good without support for X (or being able to handle condition Y), and there are many, many values of X (and Y). Small and fast plus X would still be nearly as small and fast, but small and fast plus all X is decidedly not. Meanwhile, the other engines are evolving too, and everyone more or less converges on roughly the same performance characteristics. We [I work for Mozilla] end up mainly competing on different metrics, assuming we all keep up with "good enough" speed and size.
> It says a lot about Firefox that despite being older than both Chromium / Blink and Webkit, the latter are more popular in many open source and commercial applications because of the ease of use in coding and integrating it in their applications.
Indeed it does. Firefox abandoned embeddability long ago, and only recently decided to try again with GeckoView. And yes, it was a deliberate decision, but not for the profit motivations you're suggesting. It was based on maintainability and developer velocity, when we realized we were not going to out-compete Google with engineer headcount. We had to simplify and reduce our nonessential complexity overhead.
> Mozilla also made some developers sign non-disclosure agreements
Why throw so much shade? I'm not sure exactly what you're referring to, but Mozilla does indeed sign NDAs for stuff that people will only make available under NDA, and there is some insider knowledge that can only be released under NDA or not at all. That was far more common with FirefoxOS, because let's just say that the mobile industry isn't quite as open as desktop. (Massive understatement!) But generally speaking, we have very little to gain from keeping any technical or architectural stuff private, and quite a bit to lose. We're still a community-based project, and get very substantial contributions from non-employees, admittedly much less than in that past as a percentage (for a long time, we hired up many of the better contributors, which cut both ways.) The vast majority of our discussions happen in open forums (Matrix instead of IRC now, but still mailing lists + newsgroups + various other things). The only private technical stuff I ever deal with is security-related, and even there we're very good about opening up bugs after they've shipped.