This is true, and the collective agreements set lower bounds for almost all jobs. On the flip side, employers often treat collective agreements as the only sala

This is true, and the collective agreements set lower bounds for almost all jobs. On the flip side, employers often treat collective agreements as the only salary option they're willing to offer for blue-collar positions, and the only wage increases may be the percentage bumps negotiated by the unions. In this case the only way to meaningfully increase your salary is to advance in your career. Doing the same work with double the efficiency will not be reflected in the pay. Mind you, this does not apply to white-collar positions like IT in the same manner. The salary bands are still quite strict -- 6 figures is still a rarity -- but you do negotiate them and can get meaningful raises.