"What about unmaintained Chrome or Chrome with ads?"

Your post makes no sense. No idea what you are trying to say.

What do you mean with unmaintained Chrome?

I like the idea of Vivaldi and honestly probably would use it, but I've been using Firefox as my primary browser for the last 7 years or so and just don't have a reason to switch.

I also think competition is good and am concerned if Blink became the only browser engine.