Ukraine's oligarch problem is just as troubling as Russia's oligarch problem.
However Ukraine has been trying to meet their problem head-on, while Russia never will as long as Pootie is in power. Pres. Zelensky was only elected in 2019 and before that he was a TV actor and stage performer. Zelensky is still relatively new to politics and he's making an effort to rid the Ukrainian government of the oligarchs' corruption. However it will take long time to achieve that goal I'm sure. Tough decisions need to be made and carried out.
I've recently read Marie Yovanovich's memoir "Lessons from the Edge" in which she outlines her career as a Foreign Service Officer leading to her 3-year appointment as Ambassador to Ukraine in 2016. For me the book was really an eye-opener to the problems of corruption in Ukraine and the other states of the former USSR. Yovanovich never interacted directly with Zelensky, since she was fired (by Chump) just one month before Zelensky was elected as their next President. She was later called to Congress to testify in the hearings that lead to Chump's first impeachment. What I loved about her book is her detailed explanation of the recent history in Ukraine, and the Ukrainians' firm resolve to remain separate from Putin's meddling.
The United States must continue to show solidarity with Ukraine and President Zelensky. He is taking steps to rid the country of oligarch corruption and unwanted Russian influence.