These recent developments are awesome. As a frontend developer, I also find the devtools absolutely competitive with Chrome's.
The default ad- and tracker blocking is nice, I only need to use uBblock Origin for Youtube (whitelisting only that), since Youtube became nearly unusable due to the massive amount of ads.
Edit: also, they are fortunately tackling two prominent annoyances of the "modern web" i.e. push notification popups (for those who don't turn the whole feature off outright in about:config) and video autoplay.
So sad that Firefox's market share is still just 9-10%. :(