Firefox loss in market share is more complicated. It’s mostly due to growth in areas Firefox never had a foothold. Mainly the mobile browser and the Asian market (which mostly is mobile on top of it). On the desktop front in US and especially Europe the situation isn’t nearly as dire as the global stats imply.
Firefox Android recently implemented extension support, so perhaps we will see some increased use there. But the majority of mobile users simply don’t care and considering how interlocked Google and Android is, there is little hope for a third party browser gaining a foothold.
Brave had a lot of controversies and that’s because their aggressive marketing strategy is so expensive. That’s why they did shady stuff like hijacking links and insering their own affiliate codes. Something I don’t want Mozilla doing with Firefox. Also Brave uses Chromium and the future of Chromium seems bleek. If it actually starts disabling support for adblock extensions then Brave has no future at all.
The big issue with removing the headphones jack is just that it’s now impossible to use wired headphones while charging the phone.
For a lot of people that doesn’t matter but for some of us that’s a big deal. If they added a second USB-C port that would fix the issue.
But saying the 3.5 jack is legacy technology is also kinda wrong. A USB headset is not inherently better. You have to compare the digital audio converter that’s used. While USB headphones use their own dac, the jack uses the dac of the phone. So a cheap phone with high quality USB headphones will be better but a high quality phone with cheap USB headphones would be worse than using the jack.
Which even means jacks would be more sustainable because you only need one dac per phone rather than one per headphone.
And any form of wireless headphones are just inferior to wired connections.