There's lots of very negative points rightly to be made about the Soviet Union, but lack of investment in high quality childrens books is definitely not one of them.

These things were heavily subsidised, so cheap even by USSR standards.

I've got a few Latvian language ones I'm particularly fond of. A compilation of Baron von Münchhausen stories for example - one of them the etymological source of the word "bootstrapping", or Astrid Lindgren's Ronja the robber's daughter.

Most Latvians I know, especially the ones of Latvian culture extraction, have very good reasons not to enjoy their memories of the USSR occupation, but childrens books in particular seem to be exempt. Within the boundaries the USSR set, there was an incredibly rich and high quality production. A sharp contrast unfortunately to a lot of what is currently happening in that space.

It's not everybody in Ukraine that is so froth-mouthed with their hate for USSR/Russia that they would get rid of quality books just because it's 'Soviet legacy'. Throwing the baby with the badwater spites yourself, not USSR.

There was a fair amount of non-propaganda literature published in the USSR as well.

Spivak/Perelman's books on Math have no propaganda.

Can you name popular children's books with communist propaganda in them? I don't remember any.

“Dunno in the sunny city” and “Dunno on the Moon”. The latter is rather an anti-capitalist satire.

I really love them and managed to buy both books with the original illustrations for my kid.

To my recollection, the former was a post-scarcity utopia that, like in most children's literature, east or west, didn't go too deep into the details (with the main moral of the story being 'don't be a dick to people'). I don't think it was particularly political.

The latter was satirical anti-cap propaganda.

Kinda true. The Soviet children knew there was no communism in the SU. But the book could give a clue on how it's supposed to look like.

You have children books being critical on Capitalism here in the West too.