Today's' modern mainstream browsers are all crap.
At least we agree on something. As I understand it, the main reason to use any 'secure' browser is for...well, hows about security? Now according to pretty much everyone, XP Pro was just ever so insecure since reaching the magical EOS/EOL date of 2014. According to the Cvedetails site, it has/had 685 vulnerabilities. All this everyone was always keen to tell me constantly over the five+ years I used it, along with how awful insecure the only three browsers that worked on it was. So where were all them bigtime virus, keyloggers, trojans and other bugaboos that I was always being threatened with by them that knew (or thought they knew) more than me? Apparently on every rig but mine! Why not mine? Did my state-of-the-art antivirus save me? Newsflash! Each one of the four I tried was uninstalled within a few days (too annoying). Could it of been my latest&greatest software firewall (Agnitum Outpost Firewall 2009)?
Yeah, I'm gonna credit my being bulletproof to the NAT & SPI hardware firewall of my MikroTik router, which I had a pro configure. So if security is the goal (and reason for wanting a secure browser), then I'd say it has A LOT to do with the question at hand. And in case I was not clear before, my XP Pro was a "surfing Internet machine", at least six hours pretty much every day, for over five years. That's around 10,000 hours of "you just got lucky", as one diehard tried to explain it away. As for "layer 7" monsters, where were they for the five+ years I was relegated to using Mypal, Centaury, and an outdated version of crappy Firefox? MIA. Yep, I sure must of been lucky alright. Not only dodging the bullet 685 times with XP Pro, but also all them layer 7 bullets too. Must be a miracle. Until proven otherwise, I'll stick with my assessment....all browsers are crappy, but so long as one has a strong hardware firewall (properly configured), all this OCD-like fixation on the newest&bestest and most updated is unnecessary. All browsers "are all crap", and all browsers send telemetry to one degree or another, and Mozilla is not that much better than Chromium:
https://digdeeper.club/articles/mozilla.xhtml
It just has better spin doctors, PR liars, and a larger herd of volunteer fanboys. I'll stick with Comodo Dragon over Chrome, and IceDragon over Firefox, and Epic Privacy Browser for when I'm too lazy to deploy Kodachi Linux, TENS, or TAILS. Firefox/Mozilla has well proven itself untrustworthy in the past, as the link well shows, and I'm not seeing anything to even suggest they are changing their tune these days. Not about telemetry (Google search 'firefox telemetry'), or forced updates, nor removing/disabling ever more choices to customize the browser from endusers. I'll pass on this feral puppy.