It's an extreme example, to be sure, but it is also one that had gotten a fair amount of media attention. No-one wants to work hard when they see someone else taking it easy, knowing that their next pay raise is more closely tied to seniority than it is to on the job performance.
Another example is the number of states where unions arranged "votes" to force "home health care workers" to unionize. That is, if you are taking care of a family member who recieves certain kinds of disability welfare, you are automatically deemed a union member, and the dues are taken from the welfare payments.
It was nothing more than a blatant money grab when it happened where I lived, and I can assure you that these peope got far less from their "representation" than they got in dues, since they were never technically employees in the first place and no bargaining or contact to begin with.
Yes, there are better ways that unions can operate. There are some good unions out there. There is also plenty to criticise too, and pretending that they are a universal good isn't helping anyone.
Edit: perhaps the biggest complaint is that the unions are too powerful. Even leaving is hard; the New Haven firefighters had to file a lawsuit to stop the former parent union fron sending their members to collections agencies for their dues after they left. https://www.nhregister.com/news/article/New-Haven-firefighte...
Between you, me, and the internet, I agree the seniority system is horrible, but if you don't like it, you are free to elect representatives that will abolish it. Unless of course you're in a non-union workplace, in which case you can either put up with it or quit.
As for the seniority system, unfortunately, the tyranny of the marjority is how it stays in place. First in, last out, best perks. The nature and structure of unions enables this far more readily than any merit based system. Vote all you want, but it won't change that both the company and the union are trying to screw you over. At least, that's the mentality among anti-union types in the US.
I don't think unions are universally good or bad, but they are the reason employees get paid in legal tender rather than company scrip, get weekends off rather than working seven day shifts, and why labor laws even exist. An attitude of antipathy towards unions doesn't offer a better alternative to them, as much as wish businesses and governments could just be left alone to treat labor as they please.
Just because bad things happen within and around all human organizations has no bearing on the concept of collective bargaining or working class unity, which itself is sorely lacking in the US specifically. Which means your examples amount to propaganda in favor of the investment class in the end.
If a worker does the same, it is lazy.
So it’s even worse than you portray. Companies maximizing profits is not a trade that they suffer for. It could simply be theft out of the employee’s pocket, or in the form of harm done to the environment.