When I'd visit London on business in the 80's, the homeless were very much present and visible. The concierge at the hotel told me not to leave the hotel before 6AM (I had jet lag and was headed out for a walk) because I'd be easy meat.
London really cleaned up in the 90s. There is still visible homeless, but nothing like US cities with homeless camps. Officially, there are a lot of "homeless" but far fewer "unsheltered"
I've lived in Seattle since the 70s. I never saw tents until recently.
I arrived in Seattle yesterday, staying in Ballard. Wow, it's bad here. Worse than it used to be pre-pandemic.