So a negotiated minimum wage still covers a large proportion of jobs. In Denmark somewhere around 80% of jobs are covered by the negotiated minimum wage agreements, which are typically set at $20/hr. The main exceptions making up the 20% are small mom-and-pop stores (kebab shops and such) who don't join the employer confederation and therefore aren't subject to the agreements. But all jobs at large companies, like supermarket clerks and janitors, are covered by the minimum wage.
In Denmark this was basically the social-democratic outcome of the late-19th-century labor strife: the moderate wing of the labor movement reached an agreement in September 1899 with moderates within the business community to adopt a consensus-based approach to workplace conditions and pay. That held, so both the laissez-faire capitalist advocates and the militantly socialist portion of the labor movement were sidelined for a century or so.