Here is a rule of thumb that will be familiar to many who manage risk in a professional capacity: The time to get creative is when you face a capped downside on the one hand, and an uncapped upside on the other. The time to get conservative is when you face the opposite condition. The reason for this rule is that creative policies almost never work; but when they work, they have a much higher chance of working extrao…
Herd immunity is the goal for the UK government; they are explicitly saying they want ~60% of the population to get the virus. The only concern for the UK government is to space out the rate of infection so as to avoid overloading hospitals. So they are banning large gatherings, but not doing a lockdown per se, if that makes sense. Slow the pace, but let it continue. (They may do a strategic lockdown later if necessary to flatten the curve, but right now is certainly NOT the time to do a lockdown, according to their strategy, because at this stage it would be motivated by an attempt to "stop" the virus rather than an attempt to flatten the curve.)