Last time I was there was 2019, pre-pandemic. I can't imagine it has gotten any better. I had wife and 2 teenage kids with me.
We stayed there a week, splitting time between the Donnatello and Canterbury. They are both within a couple blocks of each other.
Donnatello is closer to union square, but right on the edge of the Tenderloin.
From either resort, going East and North is better than going West or South.
When I went there, we flew in to SFO, got there really late and took a cab from the airport to Donnatello, the drive as we got closer to Donnatello reminded me of taking a cab through the lower east side or Bronx in NYC in the 70's and early 80's. The next morning I got up early and went to the closest drug store which was a Walgreens South and West of Donnatello on Geary Street (has since permanently closed I just learned). The few block walk was littered with passed out and sleeping homeless people, pools of piss, needles and all other sorts of mess. It was a real eye opener, having not been there since the 1990's. It really is a different world, closer to night the druggies are out in force, openly smoking what I can only assume is crack or meth, in additon to weed and drinking. It's wild...
Canterbury is a few blocks farther from the worst of the Tenderloin. I later found out there is a CVS a slight distance father in the "better" direction I could have gone to.
I did see poop too, so that's real, although I didn't know about "poopmaps". You can walk a couple blocks towards union square and take the cable car to the wharf or walk to Market street and take either a bus or the BART around.
It's a nice town but parts of the city are pretty disgusting. It's worth it to rent a car for a day to see some of the places it's not super easy to get public transportation to, don't park it anywhere in downtown or it will get broken into or vandalized.