Well garbage workers unions have ensured that the job is one of the best paying you can get without a degree or credential.
No formal educational credential. This category signifies that a formal credential issued by an educational institution, such as a high school diploma or postsecondary certificate, is not typically needed for entry into the occupation. Examples of occupations in this category include janitors and cleaners, cashiers, and agricultural equipment operators.
I didn't look to see if garbage workers specifically get higher salaries, but could be. But even if that's the case, it doesn't seem like a very high salary, so, assuming that unions are not in a zero-sum game, and didn't need to cause other salaries to lower, this sounds like a benefit of unions. Or is it a drawback? I wasn't sure how your statement was taken.
Given the charged and rather wanton nature of other comments in this thread, it may be being judged unfairly, though that's not my view.