By contrast, where I live in Philadelphia, developers are not required to perform any archaeological studies before excavating - even along the Delaware River waterfront, where the oldest European settlements are, as well as countless indigenous sites.
Sometimes, before history gets scraped away and sent to the dump, bottle diggers will excavate the trash pits, typically discarding anything that's not 100% intact, and selling the 18th and 19th century bottles on eBay or at flea markets. However, like the axe heads in the article, these artifacts are absent context, removing nearly all historical value. And of course, the stratification of the pits they're extracted from is also destroyed, further reducing the ability to interpret any finds that might otherwise have been saved.
It's only projects paid for by our federal government that are required to do archaeological studies, and when they do, it's not uncommon to find early colonial artifacts, but also remnants of pre-contact Lenni-Lenape sites.
You only really get one shot at recovering history through archaeology. That doesn't mean that preservation holds permanent veto over progress, but a little bit of disincentivization can go a long way in the study of history.