Again, this is where Johnson and his chums are scared to be perceived to be imposing anything, and are relying on people to interpret what their "advice" means. This results in the situations described above where nobody knows the rules ..... because there are no "rules".
In Spain (not saying it's right or wrong, just giving the example - did you know I lived in Spain
) ONLY Supermarkets and Pharmacies are allowed to be open - not DIY stores large or small, not builder's merchants, not "leisure" stores, not take-aways, etc etc) and everybody knows that, so there's clarity.