Construction unions do great across European countries.

Any company that can take advantage of workers will do it, no need for "dominant/ monopolistic".

There is a reason why security measures that put the workers life at risk are almost nonexistent on countries where unions hardly have a presence.

No helmets, no eye protection, no masks when dealing with chemicals, bending metal bars with bare hands, no protection shoes, hopping into a ladder alone,....

Some examples of what I have seen in practice.