There are old things we need that are now threatened: water and food.

Part of why they're threatened is due to lackluster planning and future mugging economics.

Humans did not “need” things they lacked, and live to tell about it. Every age could see itself as complete. We’re fortunate that it took until the mid 20th century to freeze everything in amber. Unfortunately, the mid 20th century left us some really problematic stuff that wouldn't pass regulatory scrutiny today - like car dependence - and now we can't get rid of it.