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
I’d love to help more, but it’s been years since I studied electoral systems. I’m not even sure if there is anyone currently using that system, or if it was just a theoretical election model.