Those comparisons are misleaidng and themselves the result of ideology - the local contact tracing and national contact tracing have different success rates in

Those comparisons are misleaidng and themselves the result of ideology - the local contact tracing and national contact tracing have different success rates in large part because they handle different kinds of contacts. Local contact tracing handles "complex" cases, which are generally things like workplace outbreaks where they have the help of employee records and attendance lists. National contact tracing handles all the other, less robustly recorded social contacts. I believe that in Canada, where all contact tracing is local, a lot of areas have recently abandoned tracing the kinds of contacts that are handled by the UK's national scheme altogether because they don't have the resources and it doesn't work well.