But had we locked down sooner, the peak may have been reached earlier (less spread of the virus, fewer infections) with fewer mortalities?
I do think the type of 'lock-down' we have in the UK has in itself created the circumstances where people can more easily begin to ignore the advice. ('Advice' being a key term). It has been less stringent than some other European countries and enforcement has been on a persuasive rather than a punitive basis. There are arguments in favour of that overall approach of course but a lock down environment where there's really nothing stopping me going out ten times a day if I were so inclined, where I can travel for non-essential work, where DIY stores are re-opening their doors etc. is almost designed to encourage people to start relaxing their adherence. Add to that the PM announcing with a flourish that we have now passed the peak, it's not really a surprise to see more people out and about.