[squidlogic]

There are low skilled cooks and high skilled cooks. A fast food worker is low skilled, as in, without prior skills a new entrant could do the task to a similar level of proficiency as someone who has experience.

Cooks at higher end restaurants, however, are skilled jobs. It takes years of knowledge and practice to master some culinary techniques, hence they are harder to replace, their work product can be sold for greater profit, and the individual will be able to obtain higher pay.

The same applies construction and most Amy other industry. Some jobs are low skilled, not requiring prior experience or skill, but many are skilled and can demand higher wages. This system incentivizes the individual to learn new skills, gain knowledge, try new things, and thereby gain a access to opportunities that pay higher wages.