On Android I browse by default with Firefox Focus and only to use sessions like posting this response I copy the URL to chrome and make the post. Than I'll go back to Focus. It's crude but Firefox Focus beats all browsers privacy and responsiveness on Android imo.
Once I started using Firefox Focus, I was surprised at just how much of my browsing didn't need to be logged in. I don't need to keep session state when I'm just reading Wikipedia, news sites, or blogs.
You can open more than one tab with Focus. I did it accedentally a few times. The bin action button changes to a number if you have more than one tab open.