Yes I was trained in UK. As it happens I know a fair bit about Germany.
Maybe at issue here - what has motivated the UK system. High profile child abuse neglect cases where there were judged to be failings on the part of state institutions
So Victoria Climbie for eg. So in theory, the learnings from these cases is that there should be protocols and procedures in place to catch safeguarding concerns and potential neglect and abuse. In the UK, thid would flag an internal report in a school. The safeguarding team would then discuss.
The question is - is the UK too overzealous compared to Germany. I think the only way to know this is by comparing safeguarding failures. If the German institutions havent failed children in this way, then they do not need to tighten their procedures. I dont know enough to know whether this is the case. It may well be - the German state resources social services and schools appropriately. I bet this means they are better placed to catch cases of neglect and abuse eithout needing procedures abd protocols like UK.
On an individual basis - its still daft to allow a 5 yr old to walk home. Children of this age, although capable in many ways, are simply not developed enough to be able to reliably interpret dangerous and risky situations and reliably (reliably is important here) act accordingly.
Put it like this - if something did happen. The 5 year old was killed crossing the road, the children died in a fire. Then assess the norms - i dont think there would be much difference between uk and Germany. If it ended up in the papers, public opinion would travel towards blaming the parents as negligent.
Ill say it again - please dont do this. Your most important obligation is the safeguarding of your children. Like it or not, if something bad were to happen, your absence would make them vulnerable. You cannot rely on them being very grown up and knowing what to do. They might. They might not. They wouldnt be atypical for not acting appropriately in conditions of stress. They are young children. Its your job as a parent to make sure that your actions do not leave them in a situation where they are alone and facing a threat, until they are at an age where they can reliably act appropriately.
What age can you rely on them to reliably do this? Thats a different topic - but it is not 5 (walking home alone) and its not 8 and 10 (being alone at night).