I don't think they could just let it run through. Much as they might want to.
We'd have too large a proportion of the workforce off sick (or dead), some for long periods, all at the same time.
We're relatively fortunate right now. We're still receiving a fair amount of normal service from essential (and not so essential) workers. The difficulties with food delivery slots are nothing compared to the chaos and disruption an unchecked Covid would bring.
It's not just about the deaths. Many people have posted on here about their experiences with Covid. Lots of healthy young people knocked for six for over a month.
Transport workers, power and food supply workers, care staff, teachers and other school staff, clients and customers and colleagues and managers of businesses. All off sick for extended periods.
And then there's our doctors and nurses and other health care workers. Already dying in disproportionate numbers because of the frontline risk and lack of PPE. Nobody would be around to care for the sick (Covid or non Covid).
We'd see devastating economic disruption in addition to countless deaths.
The government has acknowledged this. They've told us they plan repeat lockdowns. I think in this instance they're telling the truth.