Baloney
Easy oil is gone, however…
still plenty of coal and in a hundred years while we regrow our population a whole continent of trees.
The various metals left post big boom are more accessible than they EVER were before they mined. The only metals gone are the ones that were LITTERALLY vaporized.
Land fills would be quit the boon. All kinds of usefull shit there just for the digging up.
All those now empty houses and factories are loaded with stuff as well.
Can you just dust stuff off and be in the 21st century again in a few years? NO.
But anybody pre 1850, give or take, would think they had died and gone to heaven resource wise if they had access to all the crap that will be left laying around post big boom.