This is bonkers and a bunch of propaganda. I've been to the downtown of pro sports cities Seattle, LA, LV, Phoenix, Denver, Dallas, San Antonio, Nashville, Tampa-St. Pete, Orlando, Miami, Buffalo, Cleveland, Chicago and Milwaukee and probably four dozen times in Minneapolis in the last decade, and most of those places since the pandemic, and not a single one of those cites had an unsafe atmosphere. Full disclosure, I haven't been to San Francisco in probably 20 years, but if anything, it was way more European than every other American city I've been to. I pretty much ONLY go downtown, that's where all the fun and entertainment is.
I'm quite confident that people are conflating homelessness with an unsafe atmosphere and I think that speaks more to those who feel 'unsafe' than it does the city. If you can't handle AND EMPATHIZE with homeless people, there's probably not a city with more than 50,000 people you should visit.