Isn't it that they're also saying 'it's too expensive to live here, keep taxes low' or 'it's too expensive to live here, I won't, I'll consume things and leave rubbish and them go home [and pay tax] elsewhere'?
That's what happens when people just vote for their party for local government—politicians don't have good ideas or successful policies cause they don't have to to stay in office
SF has ranked choice voting for local seats, no primary. Anyone willing to put an (R) next to their name doesn't have a serious chance, because they're clearly just out of step with the city.
In practice elections are often quite competitive between the two major Democratic factions: moderates and progressives. Right now the mayor (Breed), state reps (Weiner, Chiu), and congressional rep (Pelosi) are moderates. The board of sups is 6-3 prog dominated, partially due to Breed becoming mayor and her seat being lost to apartment-tax Preston.
There's a shuffle happening right now due to the downstream consequences of Harris becoming VP that will result in Chiu's seat being taken by prog-allied Haney or Campos (no viable moderate is running, I believe). The rest of the progs support Campos though, so Haney is shifting toward moderate positions (e.g. supporting housing approvals) to improve his chances.