Being in a union pays off in labor court: Unions usually offer sending their legal staff instead of a lawyer that you‘d need to personally retain. This substantially reduces the costs of a court case for the employee.
See https://www.klugo.de/ratgeber/arbeitsgericht-kosten
(1) or shared, on partial wins.
https://en.wikipedia.org/wiki/American_rule_(attorney%27s_fe...
For work related cases, if you are in a union, they will foot the bill in most cases.
Stay away from courts! If your case goes before a judge, you're in casino country. Unless you're on the hook for some criminal offence, tell your lawyer to negotiate a settlement. Once a civil case comes before a judge, that usually means that there's a legal issue to be decided that nobody agrees on, which means that you can't predict how the cookie might crumble.