I don't know how things work in your country, but here in europe union sets minimum wage for a position/skill level. If you work more, you get paid more in overtime pay, if you are more skilled, usually you have higher wage.

And atleast in my work, everyone is paid more than minimum.

This isn't true and I don't know where this idea comes from

according to anti-union propaganda, that is.

(sure, that could be what the result of negotations is, but it doesn't have to be)