Russia nor China had strenght to challenge USA and West. West was never defeated as civilization. Russian economy is too small to influence major financial channels and hubs. Moscow is not Frankfurt, London, NYC, or Tokio, nor it is a financial capital. Outside major cities, Russian countryside is depopulating, impoverished, and backward, even in comparison to middle bracket countries like Poland and Hungary. I know because I drove through there. With increasing isolation on both international arena, and economics, its economy will have hard time to sustain. Just to sheer size of Russia is a problem because it needs to provide services, transportation, bureaocracy accross so many timezones, but its population is centered along two three major hubs. West is hostile, so is south with unstable Caucasus and Central Asia. War with Ukraine damaged relationship with all its neighbor even with countries that have neutral view of Russia and almost every Slavic nation. Putin's idea to attach Ukraine and Krym to Russia did not play as well. Krym is isolated and land corridor six months into the war did not materialize with southern Ukraine. Either way, Russia is heading into another lost decade of isolation as it had before 1991.
China does not want to get involve with Russian mess. They may cooperate, but they are hardly ally. China will not itself get manipulated by Russia against West and USA. In the term of economy, China can figure out that money are in USA and Western Europe than in Russia. Add to it long decades of disputes on borders and Sino-Russian suspission, the relationship is not that cozy. China cannot sustain its growh indefinitelly and any confrontation will reveal deep structural and economic problems of extensive growth in the past generation. All progress could be lost and China after riots of 1989 will not want to face angry masses. Russia is different because majority of population is extremely passive and politically disinterested except in outburst of nationalism. Russia did not experienced revolutions that swept communist party away as it happened in Czechoslovakia or Romania, or went through strike wave as did Poland, East Germany, and Hungary. Majority of population until the disintegration of the USSR actually loved the system. This a huge difference between China and Russia where one major international confrontation would swept both of them.
While USA has tons of problems and so does EU, never underestimate ability of Westerners to wage a war. In past 2500 years no single civilization ever was able to conquer them. Never.