Taxation is the skim. A secure (protected from "borrowing, just this one time, I promise, don't worry I'll put this fancy piece of paper in the box as a replacement") kitty containing these funds, is something else entirely.
Norway provides ample guidance here. They have what, a trillion dollar sovereign wealth fund, invested exclusively in non-Norwegian assets, locked away for the rainy day when oil runs out or becomes valueless. That day may now be upon them.
It's easier to do when you have massive oil reserves and a small population, however, Norway has done an absolutely top notch job imho. I 100% agree with you that we should be looking, and very closely, at Norway and any other countries whose policies in any area seem to be working exceptionally well.
I wonder if doing that would be considered a loss of face in some way.