Bingo! That's the difference between the lawyer and the chairman (or a good union rep).

The lawyer uses big words and threatens to sue, but the company has more and more expensive lawyers, and money usually wins. The lawyer then collects the big fee (from you, most likely, unless a lawsuit looks winnable in which case the fees will be 60-70% of the winnings, plus court and support costs that eat up the rest) and walks away. In non-union jobs, this is all the representation you normally can get.

The good union rep explains in simple words (HR folk don't have time to develop much vocabulary) why the job won't get done without you there to do it, regardless of what the company says you did (which maybe you actually did, but that's not the real issue if you want to keep the job or be able to work elsewhere). IOW, you are not replaceable by some random newbie. Oh yes, and doesn't have to threaten to sue - the escalation process is enough of a burden that most HR types prefer to avoid it.

A good union rep does that wherever there are unions (outside of govt and Class 1 railroads, a vanishingly small group these days). A good union rep is priceless. Some of the earlier gripes were not talking about a "good" union rep.