Who's benefiting from SF homelessness?

You may be right, but your angle of causation is wrong. California is not creating homelessness to milk money out of rich MSNBC shitlibs. They created homelessness as a side effect of them making housing very expensive... in order to placate those same rich MSNBC shitlibs who you think are being defrauded.

California's ruling class is a landed gentry of boomers that all bought into the housing market before Prop 13 froze their tax rates in place. They will weaponize anything to stop any construction which they think might lower their property values. Hell, Beverly Hills used their school district in order to launch a frivolous lawsuit against the LA Metro D line expansion, because Beverly Hills is full of rich idiots who think public transit ruins property values[0].

So California can't get rid of homelessness - not because it means the homeless shelters[1] will be out of a job, but because homeless people are the natural consequence of making housing unaffordably expensive. The only actual solution to homelessness is the one thing California will never do on pain of death. The homeless shelters are there to create moral cover for NIMBYs making the city too expensive to live in. So the homeless shelters aren't ripping off the shitlibs; the shitlibs are paying them to sweep the problem under the rug, and they are dutifully doing so.

[0] Cars ruin property values, because cars require lots of very expensive infrastructure like highways and stroads, and nobody wants to live or shop next to a giant pollution generator. In contrast, access to public transit increases land value! But the California gentry all drive so they don't care about this.

[1] Please interpret "homeless shelters" to mean "any government agency involved with homelessness management". Technically speaking SF has a lot of unsheltered homeless because, well, living unsheltered is just not as hellishly awful as it is in other cities.