I didn't say Mercedes was crumbling I said that infrastructure is crumbling. We live in a highly connected, delivery oriented Just In Time management tech world. When supply chains break down all manufacturing stops.
The other bit about the lumber mill sounds about right for our future. There may be only a few who know how to operate it but that has always been the case. We have lots of steam engines and machinery in the UK all run by volunteers and enthusiasts. Its not rocket science and anyone can learn how things work.
Yes it will be grim and dangerous. We may be living through 'peak civilisation' right now. Followed by a slow (or maybe not so slow) decline as resources disappear and people fight for what remains.