Re: Hanlon's razor
The issue about being slow to implement lockdown is debatable. There has been a lot talked about lockdown-fatigue.
Until last weekend roads have been pretty quite however there has been a dramatic, step change in traffic. On Monday there were actually queues of cars at traffic lights and significant non-commercial traffic on the M1. Given that nothing is supposed to have changed then that is an awful lot of people who are now travelling, either for leisure (unlikely at 7:00am) or are now returning to work.
This weekend there were significant numbers of cars with 2 people in driving about Saturday and Sunday. There may be genuine reasons but again, if this is for shopping then only one person should be out. The entire lockdown is pretty much a self-policing event requiring cooperation and honesty from the population. If the lockdown was started earlier it is very difficult to know if it would have ended earlier. At the moment an unknown percentage of the population has had COVID19. There is insufficient evidence that having been infected gives immunity (this is one of the key problems to developing Coronavirus vaccines) so an antibody test is not necessarily helpful other than providing statistics and testing for infection only tells you who has it at that moment in time. The final bit helps with identify and trace but again, you have to have a huge testing programme of the entire population, regardless of whether the believe they have been infected for it to work. All the apps are doing is matching positive tests against contacts. This will only achieve real progress if the number of tests (and retests) goes up.
In terms of centralised of decentralised the majority of the public don't care, those of us that do are in the minority and will just been seen as critics of something that is trying to do good.
I don't trust, Google, Apple or the Government with the information and the decentralised approach still needs an update from a central database. Both have to get their raw information from somewhere and the output of the contacts then has to be acted upon.
The big question for either approach is what happens if the take-up is not high enough to be effective.
No one has addressed this and as other articles/comments have eluded to, it is not beyond possibility that an App becomes compulsory. At that point we are into a whole new ball game.