Alternative voting systems have in practice been proven useless, whether in South Korea, Japan, Australia, and many other capitalist dictatorship countries that use it. It might make bribery a bit more expensive, since there are more candidates to buy off, and more political advertising necessary, but it hasn’t fixed anything.
The root problem is capital standing above political power. And that can’t be undone using it’s own platform.
Electoral reform not only doesn’t address root causes, it doesn’t even treat the symptoms. It hasn’t prevented australia or japan from having far right governments, hasn’t returned land to indigenous peoples, hasn’t done anything against inequality, hasn’t empowered poorer peoples. All it does is make the political bribery slightly more expensive.
At a deeper level, representative elections always result in an oligarchy. The wealthy / economically dominant classes are the only ones who have enough money / prestige to finance their campaigns and win the popularity contest. It makes any political system based on elections nothing more than political theatre.
This is basic stuff even the ancient greeks knew, and communists learned through trial and error, yet liberals in the 21st century can’t wrap their heads around it.