Whether those representative act on their own, or join a national union or syndicate, is their own decision, and they're elected every 4 years.
Any meeting or importance between an employee and his employer, he can request one of the representative be present to assist him (and in some type of meeting, it is pretty much mandatory to avoid employer pressuring against).
Etc etc ...
Our system is far from perfect, but at least having SOMEONE in the company to turn to seem to make sense to me.
In Germany, that's called "Betriebsrat" (something like "company council") with pretty much the same purpose.
And then there's the "Gewerkschaft", which are unions not for one company but for entire sectors of the economy who - through their numbers of members - are able to do collective bargaining for the employees of their fields of various companies. E.g. "IG Metall" being the industrial union of metalworkers, which considering Germanys large manufacturing background is the largest union in the country.
See also: https://en.wikipedia.org/wiki/IG_Metall
I’ve never been highly convinced by these organs, since they seem to be colonised by folks who want to become Very Difficult to Fire, and who ultimately fold to any poorly thought-through management decision that impacts the lives of employees.
I’ve come to that both as an individual contributor and as a senior manager, but YMMV.
...a government body providing impartial advice for employers and employees to improve industrial relations. I can't recommend them enough.
In many European countries unions provide free legal support.
Join the union even if things are good for you now, and you don’t have to go hunting for legal help if one day you feel like your employer isn’t being fair.