He has some interesting thoughts, and it's worth exploring his end of the spectrum but... I'd read in the same way you'd read "What if the Confederacy had won the Civil War".
It's a linear projection of the future ignoring basically all technological advances, market responses, or ability to work around logistical barriers. The world is just not that dramatic, and people mostly muddle through.
(yes, I read the book).
I think he under estimates the arrival of solutions based on economic pressure. He sights platinum as an example of extremely limited resources. I think if supplies are cut off new solutions will be found, and new mines. It’s just the best current mines are priced low enough further exploration isn’t sensible. Same with silicon production.
Oil production in the us is a good example of this. We slowef producing oil because costs were too high, and exploration wasn’t worthwhile. When costs caught up, new techniques were developed, and new fields were discovered.