Note: This subject is deeply political by definition, so I'm not sure, whether it's actually allowed by the forum rules in the first place. As a proud union man I will drop my two cents non the less
I live in Germany: Athough Germanys unions are a bit tame for my taste (they don't strike very often but prefer to do some kind of lame deal with management) , they still do a quite good job. They are weak in Industries with low membership, but even there they provide a quite good law insurance If you ever need to go to court because of an action of your boss (e.g. fireing you, cheat in your payment etc). The law department of its umbrella organisation even has a quite comprehensive website about Germans working and social law: https://www.dgbrechtsschutz.de/
Depending of the sector they have other goodies (E.G: The union of teacher and kindergarten staff has a key insurance for their members, since losing a key to a school is not only a pain in the ass for everyone involved but also quite expensive (for the girl/guy loosing the key) , others have deals with insurance companys for an accident insurance (including accidents in your leisure time ) etc).
And in sectors with big memberships, they actually do excellent work.
Two years ago automotive supplier Neue Hallberger Guss had a big fight with their most important customer (VW), where managment of NHG decided to close one of their factorys. Since about 90% of the company was organized in IG Metall, they started to strike. In the end, owners of NHG sold the factory to new owners. Although they still layed staff of: 50% of people losing the job is better than 100% lost jobs. And they mostly layed people of, who are young, had no family etc, so have a better chance to get a new job
A east german noodle factory (Teigwaren Riesa ) did a successful strike for getting a higher pay two years ago, too, but they also had 75% of the staff member of the NGG (union of gastronomy and food industry).
The same union did a great campain (called Deliverunion ) for organizing the poor guys, who devliver pizzas to people with long Kerbal sessions like me .
So yes an union membership is actually a quite good idea, especially If it's not so great at the moment: $24 if they are performing ok or good, is not a big deal for the benifts. I pay 1% of my income at the moment, because of Germans system they can't control it. If I ever would need their law support, they might ask for a confirmation of my income. That's just fair imho, their lawyers and staff need to eat too).
If you think they can do better: 24$ is also not a big deal, to get the right to vote and run for a position, to better things.
You might want to read Jane McAlevys "No shortcuts". She is a former union organizer, who wrote this as part of her academic education, to reflect what's working for getting better results and what's not.
tldnr: I'm a proud union man, always was, always will
Edit: Just saw your last replay after posting, sorry for spam. 24$ for medical insurance sounds great. Welcome to the union Kollege Spacescifi (coworker in Germany, we adress fellow unionists with this term e.G. coworker Spacescifi )