Keynes also stated that the govt should cut back when times are good. That's not going to be done by politicians.
It's been the Feds job to "Take away the punchbowl" when the party got rowdy. Unfortunately Greenspan denied all possibility of this and announced an increasing and never-ending party in 1995 until he retired. (Look at the stock market inflection of 95 to see the result.) In his farewell speech he more or less said....you can't keep doing what I've been doing.
Also your point about oil is bogus there have always been things you could point to such as 80 years from now they would likely claim the internet was the saving grace of our time.
Basically Keynesian didn't improve the economy, it helped us tread water for 10 years.
A depression with no govt. interference would have been harder but faster. The same as you are saying now.
There were many previous depressions that ended quickly this is the first (I am aware of) that major govt. "Help". (and seems to be the reason it became a "Great Depression".
The rest of the developed world buying war goods and foodstuffs is what got us out of the depression, leading into the Marchall plan. Countries that did not accept American "Help" after WWII got better faster.
BTW I agree with your agreement that both sides have a point and the present direction is a bridge to nowhere. Someday the pain will come. The longer we hold it off the worse it is likely to be.
There are likely Oil and Water wars coming. Maybe we will grow our GDP by supplying the world with arms and food again.
Not exactly a pleasant thought.
Keynes