You’re probably right, but there are other reasons. I don’t have any statistics to support my point, but looking at a (comparatively) low level of food waste in Russia, I could come up with some ideas why (based on 37 years living there):

• It’s generally frowned upon if you throw away a lot of food. Probably because most of the population didn’t have much on their table. And especially in Saint-Petersburg (Leningrad) which was blockaded, and where starvation was a real thing. My grandmother survived that, and she would always remind me of the struggle when I left something on my plate.
• Most of the population lives in cities, and even if a poor family is living in some shitty town far away from everything, the conditions can be bad, but not “dirt floor” bad, and everyone has a fridge.
• I never had to do that, and it was more of a Soviet Union thing, but in a winter, people used to hang out a bag of meat or something like that outside their kitchen window, because freezers were tiny, and that was the way to keep stuff from spoiling if you were lucky buying something cheap in bulk. I didn’t see that for many years, but I’m from a big city and maybe it didn’t get that much nicer elsewhere.