That probably is true by some measure. There are a lot of cameras in the UK - rather more than when I was a nipper!
I'm 55 and pretty well travelled and I've noted similar levels of coverage in many EU countries and the US and CA and of course CN (to be fair, my experience of CN is only HK).
I don't know why people get so whizzed up about London's CCTV coverage. For me the scariest area is the M42 south of Birmingham. Every few 100 yards there is a high level camera at height and lots of ANPR.
It is quite a logical place to concentrate on. Look at a map of England - Brum is in the middle of England and the main roads run nearby. M1 from the southeast, M5 from the southwest, then M1 and M6 (takes over from M5) carry on to the northeast and west.
My own house has six HD cameras with Frigate to co-ordinate, analyse and record. My Reolinks never get to see the internet! Four are on the garden and two watch the front door, one is the door bell.
Now ... "since the '70s": I'm old enough to remember the seventies (I still have several mugs for the Queen's Silver Jubilee in 1977, when I was seven). Back then video (VHS) was not a thing, neither was CCTV. We had three TV channels FFS! A cutting edge TV camera at the time was a huge beast and certainly was not mounted on a building or street lamp.
Ah the Silver Jubilee Mugs, we had a grey one with that weird bumpy ceramic effect.
Anyway, on the cameras you're spot on. I do wonder how much UK cameras are used though - like a microcosm of our national potential, the cameras have potential but how often are they really used: half are likely faulty, most have the person monitoring them on a tea break when something happens and it seems to need an extreme act of violence before they get used in earnest.
We lived in Manc in 1977 (Dad was a soldier and did a year at UMIST to get to Lt Col, family in tow). Then we buggered off to Germany (again). For a kiddie, I had an amazing life! We were posted to Cyprus too.
Our Jub mugs were mostly transfer printed. We had coloured ones and ones with a sort of silvery monochrome effort.
I'm not too sure that the meme that the UK is the most monitored nation in the world is too true.
You probably remember 1984. I went to a jolly posh school in Devon (Wolborough Hill School, Newton Abbot) and we had to discuss 1984 in 1984.
Do you feel too monitored? I suspect that monitoring is under-reported elsewhere.
As shocking as this is, it's not _surprising_