I just wanna say that we have Webkit. After Google moved over to Blink Webkit has not stopped development… and it even has multiple big names behind it (like Apple, but also Valve partnered with WebkitGtk maintainers, and many devices like Amazon’s Kindle are heavily invested on it) so it’s not gonna go away anytime soon. Specially with Safari being the second most used browser on the web, right after chrome and several times more users than Firefox.

On Linux we have some browsers making use of Webkit (like Epiphany, Gnome’s default browser) that are thus independent from Google or even Mozilla. I’m not sure if there’s any browser like that for Windows though.

There’s also Netsurf, they also have their own rendering libraries, but development for it is super slow, I’ve been following them for a couple decades and they still haven’t got a stable javascript engine, so it only works for the most basic of websites. The plus side is that it’s very light on resources, though.