Discussion - Set Aside Tabs and Warn on Close

What I do want from my browser: a warning that I'm trying to perform some action that I usually don't actually want to perform, but that's easy to perform on accident.

What I do not want from my browser: a forced change to my workflow with a lecture on how I'm "holding it wrong". That's for me to decide. Just give me the choice - don't constrain me for "my own good". 

I have yet to see any proposed workaround to warn-on-close that's actually a workaround. For example, this notion that the ability to restore tabs is sufficient - it's not, because it doesn't restore text that was typed in text fields in those tabs, and other such webpage state. And I don't think this can be done reliably - you might be able to do it for stock HTML widgets, but not when it's an advanced editor that maintains a lot of state server-side.

We've had warn-on-close as a UX concept for well over 30 years now. It worked wonderfully in MDI apps, and later in the first multi-tabbed browsers. Why is it suddenly uncool?