Don't most modern economies have elements of planning? I guess the USSR just had more of it or on a larger scale?
Yes, generally. Socialist countries like the PRC, where the large firms and key industries are publicly owned, rely more heavily on economic planning. However, even capitalist economies, where the large firms and key industries are privately owned, frequently the state is heavily involved in planning. This is especially true in post-WWII US, the Republic of Korea, Singapore, or even Bismark's Germany. This is sometimes called "state capitalism."
The USSR was more publicly owned and planned than the large majority of economies in history, though, so it's a useful case study.
Holodomor: hold my vodka
The 1930s famine in the USSR was certainly a tragedy, but after collectivization of agriculture, the food supply in the USSR was stabilized, and famine eliminated (outside World War II) in a region where famine was common pre-collectivization.
