And then there's Firefox Focus which has no tabs and no other new instance capability. One single window. "Focus" indeed. It still makes me twitchy, but is so far completely usable. Could do with a "fetch as desktop" mode, though.
How does this work in practice. I frequently have workflows where for example I have the AWS or GCloud console open and in parallel some kind of tutorial, documentation or help page I'm looking at. Would you go back and forth?
Yeah the one major issue is comparison shopping: you can't open multiple tabs/windows and flick between them.
Then again, "focus" might mean reading one review at a time. Or instead waiting until you're at a desktop and remembering to do it. If you forget, are you worse off or better off?
It's just a different situation. Depends on your criteria. Certainly, I've not missed it on my mobile.