One thing that I truly appreciate a ton lot is how China did not follow the Soviet way of managing administrative divisions within the country.
Like seriously, not even the preceeding Russian Tsarist Empire has ever allowed the kind of automony at higher levels of the regional governance as much as the Soviet Union did with their respective Soviet Socialist Republics (SSRs). Setting up those SSRs and leaving the entire union as some kind of grouping of federations of republics with their own system of communist party and government, rather than attempting to gradually absorbing and integrating them proved to be a recepie for disaster.
those communist parties didnot have the power to force Soviets to do there bidding otherwise Baku should have been the capital of Soviet Union. it was first among the oil production and highly educated Jewish Life. Imagine Soviet expansion based on Azeri interests or part of Afghanistan that ethnically Uzbek/Tajik/Turkmen etc already integrated to Soviets. No need to wait until 1979.
Soviet is Ukrainian creation so you have to look at things from that narrow perspective.
Also a state that has so much Turkic muslims would not have been able to built relations with Gulf Arabs like Russia have today with them.
current arrangement perfectly works fine for Russia and is attracting students/ workers and these countries are not under sanction.