a) Years at job = pay. Absolutely no pay increase or decrease for working harder or being better than average.
b) You are near impossible to fire unless you do something really dumb (caught watching porn at work multiple times, punch someone). You can be far below average and kinda sorta do your factory job and keep it for life.
Both are 1000000% against every fiber in my being, and would make me 100% never want to work at this kind of union. This is how like the autoworker and Police and teachers unions work.
There is no reason say a programmer union couldn't exist with different tools. And it could totally allow merit based pay and all of that. So by absolutely no means do I say that all unions are bad. I just know the standard American Union does not get along with my life goals.