Whereas in the old days there were men walking with barrows and a brush and scoop and it was very safe..., Now public sanitation requires a driving license, A Driving licence requires a theory and visual test, so those without reading cannot compete. Care assistant once ment just a kind heart, and endless patience, and suited slow learners,it now requires certificates, level 3 or 4 on HSE/NHS written comptency tests,with multiple choice questions. One cannot work on a building site without having a Safework pass, ..again requiring a bit of paperwork. Even the pig man of my youth collecting the swill is long gone. Coal delivery is virtually dissapeared etc.
When is the last time you saw a team of workmen digging trenches ,those mini jcb diggers do that work in hours.? , Similarity kerb laying . The add ons to small hydraulic machines cover most eventualities. Those vertical shafts are done with augers , or pile drivers which are sophisticated automation. What it means is that those people who had poor literacy and numeracy, could dissapear in the past, but cannot in the world of today.
About the only position open is fruit gathering and potato picking.