Yeah I agree that the future looks bleak for Russia, actually regardless of how well they fight. They lost, long term, when they didn't take Ukraine in 3 days. They showed a weak hand and I suspect even their ally China will treat them as a second partner and with some contempt. Perhaps the best outcome would be the Russian government falling again and this time western powers actually helping out, but I doubt they'll collapse in a way that lets that happen, or that society there will accept help, or that western countries would be interested in helping anyway.
China will decline, they're not in a great place demographically. And this is my personal opinion: China had the opportunity to become great, with just a little more freedom they could have leveraged their hi-tech manufacturing base and encouraged innovation. But instead the leadership got scared that they were losing power and sent thing in the wrong direction. It's not that they aren't innovative, it's just that has been tempered enough that they won't take the lead and all the other issues - demographic, geographic etc will take them downhill. Which is a shame because instead of a (slightly) freer world we get nationalism and unpredictability; who knows now what they'll do if they can't deliver on better living standards and an ever improving economy? Invading Taiwan would be stupid from many perspectives, but as a way to drum up and hold support of the population maybe it works?