For all the CCTV in London I've been mugged twice and nothing was captured on CCTV nor were the police all that interested in doing anything about it. As an outsider living here I think the UK has huge social problems that are neglected in favour of retaining classism. America has the same problems but at least it's more "ah, what can ya do about it huh" rather than "we are a perfect polite society British values bla bla".
The organized crime organizations just mostly focus on crime which mainly hurts immigrants and people racist police personal might not see as German even if they have a passport, and also mostly only crime which isn't publicly visible.
In turn a mixture of corrupt and racist police/politicians and having other more visible problems lead to there not being any large scale actions against them hence why they could grow to quite large size.