As you well know, there are jobs that require no prior training or education such as stocking shelves, working a cash register, and bussing tables.
Having stocked shelves, worked a cash register, worked laying concrete, been a coffee barista, and managed a grocery store.
All of which is considered "unskilled". Yet, require skills.
"Unskilled" just means no need for secondary education, or anything other than OJT (on job training). It does not mean easy work, or work deserving of min/low wage pay.
"Line cooks, farmworkers, construction workers, and grocery clerks, among others, are all considered “low-skilled labor” according to the BLS. While these jobs have few formal requirements to obtain, do they involve little or no skill to do?"
Absolutely not. Imo