I think the idea is to give employers no choice but to pay more to get workers. The fruit picking example shows that doesn't happen, you just get fruit rotting in the fields. The business can only supports raising wages so high before there is no business. Not like more expensive fruit is an option as they have to compete with the world.
They are absolutely 100% not interested in making employers pay more. They're interested in demonising immigrants and now demonising British workers who "don't want to work".
They can't get fruit picked because an unemployed person in Hull cannot afford to make themselves homeless in order to earn minimum wage for three months on a seasonal job. But the government will tell you it's because they're lazy because setting us all at each other's throats stops people noticing how much is being stolen from them.