I have two young adult children who live in zone 2. One has lived there about 4 years and the other moved fairly recently after having lived in a very pleasant and safe (or at least relatively safe, but not as safe as it used to be) small, leafy and friendly city elsewehere in the UK, where they went to uni. They also grew up in a similarly safe and pleasant environment.
Discussion ensued about commuting to work on public transport (buses and tubes) in central London and just being out and about in the streets.
Eldest said to youngest 'It's fine so long as you don't look at anyone. You will see and hear things kicking off all around you all the time. It doesn't even have to be night-time. It's constant and round the clock. Just try to look away. Don't look anyone mad or bad or shouty in the eye and certainly don't ever try to intervene in anything. It's just not worth it. Keep your head down and mind your own business, keep your wits about you, learn to sense when you need to get out of an area or situation very quickly and you'll be fine.'
That's probably very sound and pragmatic advice, but fucking depressing all the same. When I lived in and worked in central London as a young 20-something in the late 80s I commuted to work and went out a lot at night. There were certain notorious areas we all knew to avoid, especially at night, and muggings, drug dealing and gang violence were rife in those areas, but very much confined to those areas, as I recall. I rarely encountered anything scary or intimidating in my day to day travels around the city.
Now, it feels like the sheer levels of aggression and chaos and that general feeling of heightened tension are pretty much omnipresent across the city a whole. The population of greater London back then was also pretty much half what it is now, the ethnic mix much less diverse (lots of Indians and Caribbean people but very few Africans, Arabs and people from the poorer European countries for example) so we now have lots of new sectarian gang warfare issues dragged onto our streets from other places in the world.
The housing crisis was nowhere near as acute in the 80s and 90s either. There were FAR FAR fewer homeless people on the street and far fewer evidently mentally ill and psychotic people wandering around. We also have lots of beggars now, either individuals or aggressive begging and pickpocketing gangs, which pretty much disappeared post Victorian era. That was sadly reintroduced to our streets when the UK was opened up to freedom of movement from the EU in the 90s. Now it's in virtually every large town and city.
Lots of previously rough places have become gentrified it's true, Herne Hill being a great example, but the urban decay, general lack of civility and dog-eat-dog mentality seems to be more widespread in general.