Not sure why you were downvoted. This is absolutely correct and why the city is paying for street cleaning in the areas most affected, in line with the efforts of the City of San Diego in their downtown areas.

Are the street sweepers in SF effective at actually sanitizing the urine and feces or are they really aerating the excrement so any diseases contained within are more easily transmitted to passersby? I'm guessing the latter.

Why is there faeces and urine everywhere?

Large homeless population.

and a lack of public toilets. People are people — we generally would rather go to the bathroom in private if it's an option. Homeless people don't shit in the street because it's their first choice.

You can thank Richard Stallman and the toilet communism brigade.

https://stallman.org/pay-toilets.html

Can I? How much do you think someone who shits in the street today is willing or can afford to pay for private toilet infrastructure? I disagree with RMS about a lot of things, but I don't see how this would be solved without public spending.

Lack of public toilets, and a lot of people.

God, SF is so overrated.