The problem with Brezhnev was that he was a people-pleaser that did not want to rock the boat and make the nessasary reforms. By the 70s the Soviet command economy was suffering from low efficiency compared to free market + government guidance (ie Japanese economy), and in need of industrial upgrading. Instead of reforms and upgrading from a heavy-industry based economy to high-tech one, Brezhnev used engaged in all-spectrum proxy war with US across the world. USSR + Eastern bloc was already on the short end of economic stick against the collective West, and this massively sapped Soviet economic strength further and as a result USSR failed to become a high-tech economic power. USSR economy was only growing during early Brezhnev era because of the Oil Crisis of 70s, which covered up existing deficiencies and fooled Soviet leadership into continuing the status quo.
This is exactly the game US wants China to play. And this is why I despise comments that demand China to do everything it can to topple US, to interfere in affairs of other countries, or to create military alliances. All of these create massive geopolitical cesspools which will sap Chinese resources away from economic and technological development, which is exactly what US want.
