However even with all this government oversight, lots of regulation, and very large budget, they haven't been able to make a dent in the major problems like homelessness. Are they doing something wrong?
All major economies have some problems. There are no binary switches to fix or unfix a problem, especially one as complex as homelessness.
There is one obvious, and effective, fix for homelessness. Provide homes. This would run into a plethora of issues, many political, some social, but it does solve a shit-ton of issues. When the homeless are provided with homes, they tend to have fewer emergency health interventions, fewer police interactions and cost society much less than leaving them homeless. But I cannot see a nation or a state which is still arguing over whether or not healthcare should bankrupt people will go the extra steps to provide the homeless with free accommodation, especially in SF.
It is well and good for a country to accumulate debt for meaningful ends so long as the interest on that debt can be serviced. Hold the debt long enough and inflation will "pay off" the capital for you.
The belief that "Less Government" is anything other than a point at which thought stops and rationalisation begins is one I cannot grasp. There is mountains of data and counter-examples but people just stop up their ears, screw shut their eyes and thrust their heads downward hoping to find sand. Lack of regulation, particularly around poltics itself, leads to corruption and misrule. Lack of investment can lead to wastefulness.
More and stronger government is the answer to much of the UK's and US's issues in particular.