For me, it's all about the details, and I just can't come back to Firefox for silly reasons, even if I appreciate their stance on privacy.

The tabs shape is repulsing me, I know that's a strong feeling and I can't explain it. The disymetrical back and forward buttons bothers me as well. I can't find how to whitelist domains accepting cookies in Firefox. Switching profiles is much easier with chrome. I'm used to chrome developper tools.

I don't like neither safari neither MS edge.

If it wasn't for the missing onenote extension, maybe I'd be using opera. Again, all about the details.