As Ukrainian, I can answer the question. So, ultra-rich are super powerful, they own tv channels, media, bankroll political parties. Most political parties are aligned with their donors. Foreign policy is dictated by US, more or less. Zelenskiy is interesting, because he actively tries to undermine some of the existing financial groups and consolidate the power. There are presidential elections every 5 years and the same for parliament. It is very volatile, political parties have very fast churn, current parliament is something like 80% newcomers, literally.