Most of the things in the US people blame on FPTP are caused by primary elections, and California doesn't use the usual primary system because it has jungle primaries.

And IRV for local elections, but you don't see micro-parties in SF.

> Most of the things in the US people blame on FPTP are caused by primary elections

No, most of them are caused by FPTP [0], which very strongly encourages low dimensionality of political dialog and a two-party system with two roughly-equal national parties, with a strategic interest in negative campaigning and alienating voters, since driving slightly more of your major opponents voters away is just as effective as winning over votes.

Some are more precisely caused by legislative bodies with independently elected members in single-member districts.

> and California doesn’t use the usual primary system because it has jungle primaries.

Jungle primaries in no way mitigate the effects of FPTP on duopoly (they aren’t much different than majority-runoff, except that there is always a runoff even if there is a first-round majority, and the two rounds are separate by a much greater interval of time than is usually the case for majority-runoff.

> And IRV for local elections, but you don’t see micro-parties in SF.

IRV (1) is not used for most local elections in California, and (2) offers little if any mitigation of the effects of FPTP elections (it is, as the name suggests, modelled very closely on majority-runoff voting), and (3) is only used in SF for elections which are explicitly non-partisan.

[0] “FPTP” is used in a somewhat loose sense here, encompassing single-winner vote-one election methods including majority-runoff as well as plurality (FPTP in the narrow sense).