Germans cycle more than 4 times as much per capita than Brits. Absolute numbers are meaningless, you have to look at deaths per km. Germanies bike infrastructure is not great and there is lots to criticize, but that's true for most places in Europe.

https://www.researchgate.net/figure/Kilometres-cycled-per-in...

Here's a paper that attempts to do it right: Castro, A., S. Kahlmeier and T. Gotschi (2018), “Exposure-adjusted Road Fatality Rates for Cycling and Walking in European Countries”, Discussion Paper, International Transport Forum, Paris.

https://www.itf-oecd.org/sites/default/files/docs/exposure-a...

Germany does rather well. Though the paper is 6 years old (and based on numbers even older) and the number of bike accidents in Germany have gone up since then.

This data is from 15 to 20 years ago. I think the usage of bike has probably increased in the UK in the meantime. That may not change your point, but this 4 times figure is probably inacurate now.

You failed to establish a causal connection between regulating bike lights and whatever you are on about. Yes Germany is mostly car-centric (I'm not German and don't live there) and the UK is car-centric too, but I'm mostly a biker and get blinded by bike lights all the time. StVZO lights help with that.