Because of tab sandboxing.

To be honest I just trust chromium (and chrome) more. I am not even a sure why. Sort of gives me a sense of reliability, security and stability.

I had performance issues with Firefox in the past, though, but I doubt that's it.

I guess what make a me feel all tingly inside is the GUI, which I love.

How is "gives you a sense" a good reason?

I can tell you why: the excellent marketing.