>>>Desktop is extra work. You need to minimize or close the current application. The task bar is far better.
>
>Windows Key + D

Still no good. I have to alt-tab between four instances of whatever I was working on (say, four spreadsheets) plus another dozen windows I may have open or closed, and do it six times if I had six windows open and want them open again.

I know, if you press win+d twice, it will restore the previously open windows. But if you launch another app while other windows are minimized, it forgets which these were. So the memory device which will restore your environment after you erased it, for sake of adding one tool to it, is your own head - not the computer. Who's serving whom in this case?