But, there is a workaround that I use. I keep the Bookmark Manager (Ctrl-Shift-O) open on the far left of the tab strip/row and then pin it (so it doesn’t take up much space on the tab strip/row).
Now, when I close my tabs, I still have this pinned tab open and keeping the browser from closing.
I just like having a clean slate. I often have several tabs open and when I finish with them, I close them. That tells me I have nothing else to attend to on that site. Yet, I still like to have a window open. Personal preference.
The extension Don’t Close Window With Last Tab works for me, but they give no info under Privacy Practices in google web store so it’s not without some uncertainty.
I suppose if it were me I would use Ctrl+N to open a new window, Alt+Tab to switch to the previous window, and Alt+F4 to close that one. Not perfect but just a couple keystrokes, and no extensions or other modifications needed.