Actually, Russia has vast natural resources, but much of the wealth is concentrated in the hands of oligarchs. The post-communist period in Russia was marked by violent power struggles between oligarchs, often involving private militias or hired hitmen targeting rival businessmen. Perhaps it just wasn’t as visible in the US.
BTW, do not forget that most rich men in the US (Elon, Mark, Jeff) are rich on paper (stock market, company shares), while Russian millionaires have real physical control over resources or industries (eg Vladimir Potanin - rare earth elements, Vagit Alekperov - oil, Leonid Mikhelson - gas).
The father of a classmate supposedly did business in Russia during the 1990s and, according to my classmate, witnessed an execution beneath a bridge somewhere in Moscow late in the evening. I don’t remember a name of the bridge, and I can’t verify whether the story was true. However, he was completely serious when telling it, and I do remember hearing media reports about organized crime killings and similar incidents in Russia during the chaotic post-Soviet years. So while I can’t confirm this particular story, it doesn’t sound impossible for that period.