The difference is having private property and rule by the rich, vs. having state property and the democratic dictatorship of workers and farmers. China’s turn toward the semi-fascist state it is now took decades of brutal struggle against the masses by the Stalinists to deliver the blows needed to overturn the masses’ 1949 victories and restore the capitalism they have now.
It is a matter of historical record that Stalin took power at the head of a minority clique opposed to the working-class program and strategy of Lenin and Trotsky. Trotsky even analyzed the revolutionary ebb that made it possible in 2 classic works.