Thats a ridiculous suggestion.
Many of these people are totally unemployable, they have no skills at all to offer an employer, many have never worked, they are in effect useless, then chuck in MH issues, lack of education and addictions & no business that needs to make a profit will employ them.
How will get them to be a care worker or be suitable to work in a childrens nursery or become a courier?
The only thing that could work is create a job for them, a meaningless state provided one, if they don't attend 9 to 5, they lose benefits, then perhaps its possible they will gain some work ethic, though most will not, they'll do the scheme, then go back to their usual life on benefits.
I'm writing this thinking of a 26yo i know, imho he will be 50yo, still living at home and would never have worked, he has zero interest in life, work, girls or anything really, he is on a waiting list that is over 4 years for MH support.
This idea he could work in sectors we have shortages in is a joke.