Get places open again and shield over 70's/vulnerable.
You do realise that there are millions, maybe tens of millions who are vulnerable, don't you?
There are GPs, teachers, nurses, hospital consultants, who are "vulnerable" - you can't just take them out of society and lock them behind closed doors for months, maybe a year or two, and hope things will be OK. Who will do their work?
One of our neighbours is a clinical lead senior consultant at the local hospital. He's currently shielding and doing what he can at home, which isn't much as his specialism is very "hands on", so just doing basic paperwork really well below his pay grade. He says his team is really struggling as one of his registrars is also off work shielding.
Shielding people also have families to look after - elderly relatives, young children, etc.
People shielding aren't all old and unproductive, just sitting around waiting to die in care homes like some people clearly think!