Besides actually cleaning the streets, it brings very big spotlight to the problem.
And in some rare cases, if activity like this may go viral, some people in charge of public sanitation might remember of the shame enough to do their work.
San Francisco 2020 budget is ~$13 billion (https://londonbreed.medium.com/san-franciscos-budget-how-it-...)
This is the money that is supposed to pay for cleaning the streets and many more things.
For comparison, Austin budget is $4.5 billion (https://www.kvue.com/article/money/economy/austin-city-counc...)
What you see is unbelievable corruption and incompetence of city government, not the lack of money for cleaning the streets.
It's as competent as the work you put in to make it competent