Because they don't have to concern themselves with things like budget or profitability, since they're funded by the government.
Animation costs a lot to make, so cartoons made in capitalist nations need to be
1) Easy to replicate, so you can hire a ton of people to churn out your product as fast as possible and don't have to waste time and money teaching your artists how to draw each character. This means that every character will by and large use the same three designs, just with different proportions and surface details
2) Cheap to animate. Different countries have different approches to this (america uses characters made out of flat, geometric shapes that take five secconds to draw, japan uses tons of holds and looping/cycled animation, ect), but by and large it means cuting as many corners as possible
3) Marketable. You need to either appeal to a niche demographic of nerds who will buy every single piece of merch you put out at least twice, or kids who force their parents to buy them toys. Making anything remotley artistic is out of the question unless you throw some waifus in to attract the nerds
That's why capitalist nations have strugled to produce any quality animation for any extended period of time. It's very hard to make good animation that's also profitable
Communism is by and large a shitty system, but it's probably the nicest one to live in if you're an animator