I’m not very well-versed on all this but it seems
First Past The Post
Benefits the two parties in a two-party duopoly system like that of the US. Boom or bust, black or white. When the party in power pisses you off you vote their competitor even if holding your nose.
Seems like there must be a better way, maybe just not as good for those who prefer shooting fish in a barrel
Ranked choice is one of the simplest ways to get a more representative, but to the question in the title it does tend to favour centrist parties. Progressives will vote for a centrist over a conservative, and a conservative will vote for a centrist over a progressive, so the centrist party will win almost every time.
It’s still an improvement over the disaster of FPTP because it will at least elect parties that the majority can tolerate, but there is still a bias present.
That’s not a bug. It’s the entire aim of an electoral system.
The people who aren’t the extreme ends of two poles and actually have policies the majority are in favor of are the people who are supposed to be in office. I shouldn’t be choosing between “arrest people for using birth control” and “eat the rich and disband the police”.
You also don’t get progress in any direction when both parties are spending half their time unraveling everything the last group did.