If Tesco had to pay all it's staff £10 an hour, they would adjust their business to eliminate most of the unskilled roles.
They already are. Tesco make around £14,000 profit from each employee; that figure would be higher if they had fewer employees so it's in their interest to reduce staff. The taxpayer basically funds them to have lots of people in unskilled roles.
We fund these jobs because there's already a job shortage. It's just a way of faking employment, at taxpayers' expense. Even so there aren't enough jobs.
If every vacancy was filled by an unemployed job seeker, only 10% of the seekers would get a job. The other 90% would still be unemployed and there would be NO vacancies. This includes part-time jobs with unsocial hours, by the way.
The problem isn't like a household budget. Unless we stop the rich (people and corporations) funnelling taxpayers' money out of our economy without putting it back, we will all end up in the gutter. As I said before, corporate giants will not walk away from a huge revenue stream if they're made to put more back in & reduce profits. Right now, we're simply giving money away and saying "Never mind, our vulnerable people can make up for it." Soon it will be "Our working classes", then "Our middle classes".
I'm not exaggerating, this is common sense and we need to grow some balls/ovaries!