That would be absolute madness though because everyone who works Mon-Friday would have to go on a Saturday and it'd be overloaded and unbearable for everyone. The most logical thing if you wanted shops to close an extra day would be a midweek closure which is often localised and still in practice.
I'm not sure why you're in favour of a Sunday close though.
Shops never used to be able to open on a Sunday and everyone's trade was spread out over the other 6 days instead. Not everyone goes shopping on the weekend as many have days off in the week.