Ranked choice voting is more relevant for elections where one winner must take all (for instance presidential elections or voting districts with only one representative) which will always suffer from not being able to represent everyone

Direct proportional representation gets around that problem by avoiding situations where one person has to "win" an election

As for the president problem, you can get around that by simply not having a president with any meaningful power. The prime minister can be appointed by the cabinet, and the head of state (be it king or president) can be a purely ceremonial role.