Cleaners, bus drivers, refuse workers, retail staff, hospitality workers, nurses, garage mechanics, gardeners, double glazing installers, boiler installers, emergency workers, postal workers, meter readers, traffic wardens, car park attendants, doormen . . . and many more.
Most of the above have no realistic option of working from home, never mind actually owning a home they could sell to move away.
Still, I guess if there's a mass exodus from the major UK cities, homes may become cheaper . . . unless holiday homes in London/Manchester/Birmingham become the next big thing