Putin has been arguably quite successful in restoring Russia from the brink of destruction, brought back some degree of prosperity, restored Russia's influence on the international stage (as far as the global south is concerned), and is successfully challenging western imperialism, so he will likely never lose an election. He is genuinely popular. But he is 70 years old. At some point he will retire or die and there is no other figure among the bourgeois parties with the same kind of popularity in Russia. At that point the political struggle will begin again in earnest and the KPRF will have a chance to make the argument that a return to socialism, perhaps in a form that takes inspiration from the proven success of the Chinese model, is the only way forward for Russia if it wants to continue to increase prosperity for the overwhelming majority of people and prevail in the struggle against imperialism.