But [Firefox] became irrelevant after Google in 2008 released Chrome, a faster, more secure and versatile browser.
The Gray Lady gets it wrong again. Google Chrome is proprietary software, software that does not respect a user’s freedom and community. There’s no way to back up any claim of proprietary software being “secure” because there’s no way to determine what proprietary programs do or stop them if one discovers they do something harmful (malware). Proprietary software is often malware. Users lack the permission to inspect the program’s source code, alter the program, or distribute altered versions. Furthermore Google is a known international spy agency. There’s good reason to believe that Google Chrome spies on all of its users, behavior users are unlikely consider “secure”.
Firefox, by comparison, was never proprietary. Users were and are free to run, inspect, share, and modify Firefox; these freedoms are collectively known as “free software”. In fact, these freedoms are likely a main reason why TorBrowser (and so many other derivative browsers) are based on Firefox.
Software freedom isn’t about guaranteeing the user security, it’s about addressing the inequity between users and developers inherent in non-free software. Technical advantages and popularity are ephemeral. Technical features are apparently only as far away as a developer who wants to take the time to improve the program. People can and do learn to become software developers. And free software’s technical merit can be improved by anyone willing to do the work. Ergo we can add impressive technical features to free software. But we can’t make proprietary software free. So the path to getting software we can evaluate against a claim of “security” and back up that claim starts and ends with software freedom.