Sorry, but drug screening is a completely valid and necessary safety measure for many professions, including anyone who works with heavy machinery or industrial equipment. Most jobs are not in silicon valley, and people can be hurt or killed when an employee shows up intoxicated.

Drug tests of the sort performed by LabCorp don't test whether an employee is showing up to work intoxicated. And they don't apply only to those professions where it's valid and/or necessary, but to pretty much any where the employer feels they can get away with it.

Why would an employer test employees, at the company's cost, unless they felt like it was in the company's long-term financial or regulatory interests?

We actually do randomized tests for intoxication of employees