One thing about San Francisco is exactly the same thing as any other city. It has problems, usually localized to a few neighborhoods, with bad city services, crime, and homelessness. The thing about San Francisco that is different is a whole lot of people bid up the price of housing even in the crappy neighborhoods, hoping to ride the wave of gentrification, only to find out you can't gentrify the entire city because the poor and the homeless don't just evaporate by sheer force of will. Now they're left in still crappy neighborhoods, but with homes they paid 7 figures for, or 3k a month a rent in places they don't even own.
Buuuut, crime actually is abnormally high there.
If you just look at crime trends, violent crime in San Francisco has trended downward pretty consistently for decades, but slower than nationally and across California. Property crime has actually gone up, which is the most atypical thing, because it's gone down most everywhere else. San Francisco is the fourth biggest city in California. So what about the fourth biggest in Florida? Orlando has seen both property and violent crime rates drop quite a bit, but they were absurdly high for some odd reason 20 years ago. They're still higher than San Francisco on violent crime, but lower on property crime. Fourth biggest city in Texas is Austin, which is quite a bit lower than both Orlando and San Francisco on both property and violent crime, close to Texas and national averages. New York only really has one city, and it's a little bit lower on violent crime, and drastically lower on property crime.
So all in all, it seems like San Francisco has an abnormally high property crime rate. People seem to love pinning this on Prop 47, but property crime rates have actually always been abnormally high in San Francisco. It's worth noting Prop 47 is statewide, yet property crime rates double the state average is just a San Francisco thing. Los Angeles is almost the same as the statewide average.
So whatever the heck is actually the problem, it's specifically a San Francisco thing. Unfortunately, since I don't think it really fits standard red/blue culture war narratives, no one is incentivized to figure out the real reason and do anything about it.
Something interesting is to compare to other places that were the site of some type of "gold rush" that is the reason the city even exists. South Africa and Congo have been in terrible shape forever, at one point murder and kidnapping capitals of the world. Even the Yukon Territory in Canada has among the highest crime rates in the country, in spite of being largely rural.
Way before anyone ever wrote Twitter take downs of tech bro gentrifiers, California's first millionaire, Samuel Brannan, was the richest man from the gold rush, but he never even found gold. He just bought up all the retail space and sold shovels, pick axes, and pans at a ridiculous markup. When his speculation drove up the price of land, it led to something called squatter's riots when people being made homeless got pissed, and he formed an extra-legal "vigilance committee" to be a sort of private police force that rounded up and hanged people before California became a real state and has actual laws.
I'm not sure there's a real point there, except to speculate about the possibility of some sort of centuries spanning cultural inertia that forces a place to maintain the same character it was founded with long after there is still any good reason for it.