Yet, when the Soviet economy was publicly owned and planned, from 1928 to 1989, it reliably expanded from year to year

This claim is laughable considering that the vast majority of Soviet citizens lived in abject poverty during that period, and the whole system collapsed due to lack of money. If the economy was "reliably expanding" then why were their bread lines?

The infamous bread lines, people queuing up before dawn to get milk, scarce produce, bare shelves at supermarkets and empty clothing stores became an everyday reality. We didn’t have connections to The Party, nor veteran benefits—as both sets of my grandparents were too young to fight in the war—so we lined up like everyone else. Often, the distribution of food was limited to a certain number of pieces per person. I was frequently dragged to stores by grownups in my family so we could get two packs of detergent instead of one. Or two loaves of white bread instead of one. Or two pea coats. Whatever appeared in stores nearby.

https://www.forbes.com/sites/katyasoldak/2017/12/20/this-is-how-propaganda-works-a-look-inside-a-soviet-childhood/

There was nothing economically successful about the USSR, it brought poverty to its entire population, aside from a handful of powerful political figures who enriched themselves at the expense of everyone else.