Soviet economy did not 100% follow the ideology of central planning. Black market always existed (and probably helped many people survive), and when critical things started collapsing, exceptions were also made officially.
Also—not sure how important was this—Soviet Union got some fresh vassal states after WW2.
And even when the economy is dysfunctional, you can get some extra income from selling raw resources.
(But technically I agree that most libertarians would probably underestimate how much extra time this can win.)
Soviet economy did not 100% follow the ideology of central planning. Black market always existed (and probably helped many people survive), and when critical things started collapsing, exceptions were also made officially.
Also—not sure how important was this—Soviet Union got some fresh vassal states after WW2.
And even when the economy is dysfunctional, you can get some extra income from selling raw resources.
(But technically I agree that most libertarians would probably underestimate how much extra time this can win.)