Your thoughtful and measured response is much appreciated. Cheers for that.

A big problem, in the context of our approaching year three of intermittent lockdowns and restrictions, is that large numbers of people, how should I put this, are getting bloody fed up of being told what to do by a government that is looking increasingly incompetent. Perceptions of the apparent absurdities we're talking about won't generally be subjected by most people to the kind of careful consideration that you exemplify in your post. The apparent superficiality of my supermarket/pub example is likely to be the far more typical response. The population has, so far, been very compliant in general. A government that continues to rely on that, in the face of what look like heavy-handed edicts, could be taking a risk. I still think that education, information and persuasion are the pragmatic way forward (this virus isn't going away: it isn't like an outbreak of food poisoning or typhoid or even winter flu. We can't be telling people to wear masks for year after year...). Never compulsion.